Insiders Lingo

Same word, different worlds

One word, many meanings

225 words that mean one thing to a welder and something else to a surveyor, a chemist or a railroader. Use the wrong meaning in the wrong room and everybody knows you are new.

Bump

  • Machine Shop: To make a small adjustment to an offset or position, usually a thou or less, to bring a size in.
  • Electrotechnology: To energise a motor for a split second to check its direction of rotation before running it properly.
  • Boilers: To energize a motor, pump or burner for a second or two to check rotation or operation.
  • Lighting: To flash a channel or group to full instantly, usually with a console button, to identify it or for effect.
  • Asphalt: To push excess mix off the old side of a joint back onto the hot mat with a lute so the rollers can pinch it...
  • Railroad: To use seniority to take a job held by someone junior, who is then displaced.

Spalling

  • Tribology: Flaking of large chunks from a bearing race or gear tooth after fatigue cracks below the surface link up.
  • Thermal Spray: Flakes or chunks of coating breaking away from the surface, typically under thermal cycling or impact.
  • Refractories: Cracking off of pieces or layers from the hot face of a refractory lining.
  • Gears: Large, irregular flakes broken out of a tooth surface, usually where pits have grown and joined.
  • Concrete: Chunks or flakes breaking away from a concrete surface or edge, often from corroding rebar beneath.
  • Waterproofing: Concrete, brick or stone breaking off in flakes or chunks at the surface.

Core

  • Fiber Optics: The central glass region of an optical fiber where the light actually travels.
  • PCBs: Fully cured laminate with copper on both sides, etched into inner layers and bonded with prepreg into a...
  • Concrete: A cylinder of hardened concrete drilled out of a structure to test its strength or inspect its condition.
  • Asphalt: A cylinder of pavement drilled out of the finished mat and sent to the lab for density and thickness.
  • Nonwovens: Tube, usually paperboard, on which nonwoven fabric is wound to make a roll.

Fines

  • Thermal Spray: Powder particles smaller than the specified size range, which cause buildup, spitting and poor flow.
  • Powder Coating: The smallest particles in a powder, roughly under 10 microns, which fluidize, charge and recycle poorly.
  • Refractories: Smallest particle fraction of a refractory mix, which fills the gaps between coarse grains and forms the bond.
  • Paper Optics: Fiber fragments and small particles that pass a fine screen and have an outsized effect on sheet optics.
  • Asphalt: The dust-sized part of the aggregate passing the No. 200 sieve, which stiffens the binder into a mastic.

Hot spot

  • Corrosion: Localized area of active corrosion on a pipeline, or the targeted anodes installed to protect just that spot.
  • Refractories: Area of a vessel or kiln shell running hotter than normal because the lining behind it is thin or gone.
  • Nuclear: A small spot on piping or equipment with a much higher dose rate than its surroundings.
  • Lighting: A distractingly bright patch in a beam or on a lit surface, brighter than its surroundings.
  • Photonics: A small region of a beam with much higher intensity than the rest, a common cause of optic damage.

Kick

  • Adhesives: To gel or cure suddenly, as in a resin kicking in the cup or a CA kicking with accelerator.
  • Electrotechnology: Shop verb for a breaker, overload or relay tripping, as in the breaker kicked.
  • Photonics: To start a Kerr-lens mode-locked laser by briefly disturbing the cavity so a pulse can form.
  • Concrete: To start setting, usually sooner than the crew expected; a load that kicks stiffens fast.
  • Railroad: To shove a cut of cars, uncouple it on the move and let it roll free onto a track.

Shot

  • Tribology: One full stroke of a manual grease gun, the everyday unit for how much grease goes in.
  • Welding: Shop word for a radiograph of a weld, or the act of X-raying it, as in the weld got shot.
  • Nuclear: A single industrial radiography exposure, used to x-ray a weld with a gamma source or X-ray tube.
  • Photonics: A single laser pulse, especially from a high-energy or low-repetition-rate system.
  • Nonwovens: Small beads or lumps of polymer that failed to form fibers and sit embedded in a meltblown web.

Bleed

  • Tribology: Separation of oil from a grease, either as a storage problem or as the intended release of oil to a bearing.
  • Boilers: To let trapped air out of a hot water radiator, baseboard or high point by opening its small vent until...
  • Waterproofing: Staining from fluids or plasticizers that migrate out of a sealant into porous stone or masonry.
  • Vacuum: To admit a small, controlled flow of gas into a vacuum system through a needle or leak valve.

Coupon

  • Thermal Spray: A small test piece sprayed alongside production parts to stand in for them in destructive tests.
  • Adhesives: A small standard test piece, usually a metal or plastic strip, bonded to check adhesive strength or prep.
  • PCBs: Small test pattern built on the production panel and measured or sectioned to prove the boards meet spec.
  • Geosynthetics: Narrow strip cut across a seam sample for peel or shear testing, usually one inch wide.

Delamination

  • Thermal Spray: Separation of a coating from its substrate or of one coating layer from another.
  • PCBs: Separation between layers of a board's laminate or between laminate and copper, usually from heat or moisture.
  • Concrete: A surface layer that has split away from the concrete below it, found by the hollow sound it makes when...
  • Nonwovens: Separation of the layers of a laminate or multilayer nonwoven, such as an SMS or a film composite.

Holiday

  • Corrosion: Pinhole, void or bare spot in a coating that leaves the metal underneath exposed.
  • Powder Coating: A skip, void or pinhole in the coating where bare metal is exposed.
  • Waterproofing: A gap, pinhole or thin spot in a membrane or coating where it fails to cover the substrate.
  • Hydrography: A gap in survey coverage where no data was collected, which must be filled before the survey is complete.

Pigtail

  • Electricians: Short length of wire spliced to several conductors so only one lead goes to a device terminal.
  • HVAC: A short jumper wire spliced into a group of conductors so they can share a single terminal.
  • Boilers: A looped siphon pipe between a steam boiler and its pressure gauge or control, filled with condensate to...
  • Fiber Optics: A short fiber with a factory connector on one end and bare fiber on the other, spliced onto a cable to...

Purge

  • Tribology: To pump fresh grease into a bearing until the old grease is pushed out of the relief port or seal.
  • Adhesives: To run adhesive through a mixer or dispense valve and discard it, clearing old, unmixed or off-ratio material.
  • Welding: Inert gas flowed inside a pipe or behind a joint to keep the back of the weld from oxidizing.
  • Boilers: Blowing air through the furnace and flue before ignition or after shutdown to clear out unburned fuel.

Shoot

  • Thermal Spray: Booth verb for spraying a coating onto a part or coupon.
  • Powder Coating: To spray powder, as in shooting a part or shooting a color.
  • Fiber Optics: To test a fiber with an OTDR, as in shoot the fiber or shoot it from both ends.
  • Asphalt: To take a reading with a nuclear gauge or infrared gun, as in shooting density or shooting a load's...

Stinger

  • Refractories: Shop name for the immersion vibrator head pushed into fresh castable to consolidate it.
  • Welding: Shop name for the electrode holder that grips a stick rod and carries welding current to it.
  • Electricians: Lead that drops from a pole-top fuse cutout to a transformer's primary bushing, in lineman and service talk.
  • Concrete: An internal concrete vibrator, or specifically the vibrating head on the end of its flexible shaft.

Undercut

  • Thermal Spray: A recess deliberately machined below finished size so the coating can fill it to full thickness.
  • Welding: A notch the arc melts into the base metal beside the weld toe that the weld metal never fills back in.
  • Gears: A notch cut into the base of small-pinion teeth when the generating tool removes part of the working involute.
  • Geosynthetics: Digging out soft or unsuitable subgrade below grade and replacing it with better fill.

Adhesive failure

  • Thermal Spray: A bond test break at the coating-substrate interface, meaning the coating let go of the base metal.
  • Adhesives: A break at the interface between adhesive and part, leaving one surface clean or nearly clean.
  • Waterproofing: A sealant pulling cleanly away from one joint face, leaving the substrate bare.

Anchor profile

  • Corrosion: Peak-to-valley roughness that blasting cuts into steel so a coating can grip, given in mils or microns.
  • Thermal Spray: The peak-and-valley roughness grit blasting leaves on a surface, which the coating locks onto.
  • Powder Coating: The peak-to-valley roughness that blasting cuts into steel, giving the coating something to grip.

Barrel

  • Thermal Spray: The long tube on an HVOF or detonation gun where particles are heated and accelerated before exiting.
  • HVAC: Shop name for a chiller's shell-and-tube evaporator or condenser vessel.
  • Fiber Optics: Installer slang for a fiber adapter, the double-ended bulkhead part that joins two connectors.

Break

  • Paper Optics: Tear of the running paper web on the machine, which sends everything to broke until the sheet is rethreaded.
  • Concrete: A cylinder strength test result, or the crushing of cylinders in the lab.
  • Asphalt: The point when an emulsion's water separates and the asphalt droplets fuse, turning the film from brown to...

Burn

  • Fiber Optics: Splicer slang for making fusion splices, from the electric arc that welds the glass.
  • Concrete: To steel-trowel a slab again and again at high blade pitch until it turns hard, dark and glossy.
  • Asphalt: Lab shorthand for an ignition oven test, or the binder content result that comes out of it.

Cap

  • Welding: Shop word for the final layer of passes on the face of a groove weld, the cover pass in code language.
  • HVAC: Short for capacitor, the part that gives compressor and fan motors the phase shift they need to start and run.
  • Geosynthetics: Final cover system placed over a closed landfill or waste area to keep water out and control gas.

Chatter

  • Valves: Rapid, violent opening and closing of a relief or check valve that hammers the disc against the seat.
  • Machine Shop: Self-sustaining vibration between tool and work that screams, leaves a wavy pattern and kills tools.
  • Electrotechnology: Rapid repeated opening and closing of relay or contactor contacts, usually from marginal voltage or vibration.

Clearance

  • Electrotechnology: Straight-line air gap between two conductive parts, the dimension that decides whether a surge can flash...
  • Nuclear: The release of materials with very low radioactivity from regulatory control, so they can be reused or...
  • PCBs: Minimum spacing between copper features of different nets, or between copper and the board edge or holes.

Cohesive failure

  • Thermal Spray: A bond test break inside the coating, with coating left on both halves of the test specimen.
  • Adhesives: A break that runs through the adhesive itself, leaving adhesive on both parts.
  • Waterproofing: A sealant tearing apart within itself while staying stuck to both joint faces.

Cold joint

  • PCBs: Solder joint that never got hot enough to flow and wet properly, leaving a dull, grainy and unreliable bond.
  • Concrete: An unplanned seam left where fresh concrete was placed against concrete that had already begun to set.
  • Waterproofing: The seam where one concrete pour meets a later one, a classic leak path in below-grade walls and slabs.

Creep

  • Adhesives: Slow, continuing deformation of an adhesive under a constant load, which can end in failure over time.
  • Refractories: Slow, permanent deformation of a refractory under steady load at high temperature over hours to years.
  • Geosynthetics: Slow, continuing stretch of a geosynthetic under a constant load over time.

Dew point

  • Corrosion: Temperature at which moisture condenses from air; specs keep steel at least 3 C above it for blasting and...
  • Heat Treating: The temperature at which water vapor in a furnace atmosphere condenses, used as a gauge of carbon potential.
  • HVAC: The temperature at which air becomes saturated and water starts condensing out when it is cooled.

Dusting

  • Thermal Spray: Fine, cooled overspray that settles on a surface as loose powder and weakens the next layer sprayed over it.
  • Powder Coating: A light, quick pass of powder that barely covers, or the first thin pass before building film.
  • Concrete: A soft, powdery concrete surface that rubs off under traffic or a scraped fingernail.

Fishmouth

  • Valves: A saddle-shaped cut on the end of a branch pipe so it sits flush against the curve of a larger pipe.
  • Geosynthetics: Wrinkle or bulge in the top sheet of a seam overlap that stops the two sheets lying flat for welding.
  • Waterproofing: An open wrinkle at the edge of a membrane lap that forms a channel water can run into.

Flash rust

  • Corrosion: Thin, quick layer of rust that forms on freshly blasted or water-washed steel within minutes to hours.
  • Thermal Spray: A thin rust bloom that forms on freshly blasted steel when it sits in humid air before coating.
  • Powder Coating: A thin orange rust bloom that forms within minutes on wet, freshly cleaned steel.

Galling

  • Tribology: Severe adhesive wear where sliding metals seize and tear, raising lumps of transferred metal.
  • Fasteners: Adhesive wear where thread surfaces cold-weld and tear under load, seizing a nut partway down a bolt.
  • Valves: Severe adhesive wear where loaded metal surfaces slide, cold-weld together and tear material out.

Hot

  • Electrotechnology: Shop word for live or energised, and in North America the everyday name for a phase conductor.
  • Electricians: Ungrounded, voltage-carrying conductor of a circuit, and as an adjective anything that is live.
  • Nuclear: Radioactive, contaminated or giving a high dose rate, in plant speech; the opposite of clean.

Hydrogen embrittlement

  • Corrosion: Loss of ductility when atomic hydrogen gets into steel, leading to sudden cracking under stress.
  • Heat Treating: Loss of ductility in high-strength steel when absorbed hydrogen causes delayed cracking under stress.
  • Fasteners: Delayed brittle cracking of hard steel fasteners caused by hydrogen absorbed from plating, cleaning or...

Lift

  • Concrete: One layer of concrete placed in a wall, column or mass pour, or the height cast between horizontal joints.
  • Asphalt: One layer of mix placed and compacted in a single pass of the paver.
  • Geosynthetics: One layer of fill placed and compacted at a time, the unit by which walls, slopes and embankments are built.

Mil

  • Thermal Spray: One thousandth of an inch (25.4 micrometers), the usual North American unit for coating thickness.
  • Powder Coating: One thousandth of an inch, exactly 25.4 microns, the everyday unit for coating thickness in North America.
  • Geosynthetics: One thousandth of an inch, the unit North American crews use for geomembrane thickness.

Mud

  • Refractories: Shop word for the clay used to plug a blast furnace taphole, and bricklayers' word for mortar.
  • HVAC: Duct mastic, the thick paste brushed over duct joints and seams to seal them airtight.
  • Concrete: Jobsite slang for fresh concrete, used by finishers, pumpers and ready-mix drivers alike.

Outgassing

  • Powder Coating: Gas escaping from a porous substrate during cure and blowing pinholes, bubbles or craters through the film.
  • Waterproofing: Gas escaping into curing sealant or membrane from punctured rod or damp concrete, leaving bubbles and...
  • Vacuum: Slow release of gas from the surfaces and bulk of materials inside a vacuum system.

Pickup

  • Tribology: Metal transferred from one sliding surface onto another, seen as smeared lumps after adhesive wear.
  • Electrotechnology: Threshold at which a protection element starts to operate, and the moment the measured value crosses it.
  • Asphalt: Mix sticking to roller tires or drums and tearing out of the mat, leaving pockmarks behind.

Pitting

  • Tribology: Rolling contact fatigue that leaves visible craters on gear teeth or bearing races.
  • Corrosion: Localized corrosion that drills small, deep cavities into metal while the surface around them stays nearly...
  • Gears: Surface fatigue of gear teeth that breaks out small craters, typically on the flank just below the pitch line.

Points

  • Heat Treating: Shop shorthand for Rockwell numbers, as in a part running two points high on hardness.
  • Powder Coating: The titration reading for a washer bath, given in milliliters of titrant and used to judge bath strength.
  • Paper Optics: Mill shorthand for units of brightness, opacity or whiteness on their percentage or index scales.

Pull

  • Heat Treating: To take a load or part out of the furnace, usually on its way to the quench or at the end of a cycle.
  • Fiber Optics: A cable pulling operation, from setup at the feed end to the cable arriving at the far vault.
  • Asphalt: One continuous paving pass from the start to the end of a run, or the lane width paved in that pass.

Spitting

  • Thermal Spray: A gun shedding blobs of molten buildup into the coating, leaving lumps known as spits.
  • Powder Coating: Powder bursting out of the gun in clumps, leaving lumps and heavy spots on the part.
  • Boilers: Describes a steam radiator vent that throws out water and steam instead of just air.

Sweep

  • Machine Shop: To rotate an indicator in the spindle around a bore, boss or circle to find its center or check alignment.
  • Electricians: Long-radius conduit elbow, common in underground PVC runs, that makes pulling big or long cables easier.
  • Hydrography: A search that drags a wire or bar at a set depth to prove an area clear of obstructions to that depth.

Tack

  • Adhesives: The stickiness of an adhesive surface: how quickly it grabs another surface with light pressure and short...
  • PCBs: To solder one or two pins of a part first to hold it in place before soldering the rest.
  • Geosynthetics: To spot-weld overlapped geomembrane with a hot-air tool so it stays aligned before the final extrusion weld.

Trace

  • Gears: The printed plot of a tooth's measured profile or helix from a gear checker, read against tolerance bands.
  • Fiber Optics: The graph an OTDR produces, plotting returned power in dB against distance along the fiber.
  • PCBs: Copper conductor path etched on a board layer, connecting pads, vias and planes.

Whip

  • Welding: The short, flexible lead between the main welding cable and the stinger, or a whipping rod motion.
  • Electricians: Short flexible conduit or cable assembly with wires already in it, linking a fixture or machine to a...
  • HVAC: The short length of flexible conduit and wire running from the disconnect to an outdoor unit or air handler.

Wicking

  • Adhesives: Describing very thin adhesives that run into already assembled joints by capillary action.
  • PCBs: Solder or plating chemistry drawn by capillary action where it is not wanted, up a lead, into a via or along...
  • Nonwovens: Capillary movement of liquid along or through a fabric, measured as how far liquid climbs a strip in a set...

All-thread

  • Fasteners: Shop name for threaded rod: steel bar threaded end to end, cut to length for hangers, anchors and long studs.
  • Electricians: Steel rod threaded along its whole length, used to hang conduit, strut and fixtures from the structure.

Angry pixies

  • Machine Shop: Tool-teardown slang for electricity, the invisible little creatures that bite when you get careless.
  • Electricians: Joking name for electricity itself, especially when it escapes as sparks, smoke or a shock.

Aperture

  • PCBs: Shape and size used to draw or flash a feature in Gerber data, named for the opening in a photoplotter's...
  • Geosynthetics: Open space between the ribs of a geogrid or between the strands of a woven geotextile.

Backscatter

  • Fiber Optics: The small fraction of light scattered in the fiber that travels back toward the source, which OTDRs measure.
  • Hydrography: The strength of sound returned from the seabed, used to map bottom type alongside depth.

Bake

  • Fasteners: To heat plated high-strength fasteners soon after plating so absorbed hydrogen escapes before it cracks them.
  • PCBs: To heat bare boards or moisture-sensitive parts in an oven to drive out absorbed water before soldering.

Bake-out

  • Thermal Spray: Heating oily or porous parts before blasting to drive out absorbed oil that would ruin the bond.
  • Vacuum: Heating a vacuum system while pumping to drive off water and other adsorbed gas and lower the base pressure.

Ballast

  • Lighting: The device that starts and limits current to fluorescent and HID lamps, which would otherwise draw unlimited...
  • Railroad: The bed of crushed rock under and around the ties that holds the track in line and drains water away.

Basis weight

  • Paper Optics: Weight of a 500-sheet ream cut to a grade's basic sheet size, used in North American paper trade.
  • Nonwovens: Mass of a nonwoven per unit area, almost always given in grams per square meter.

Bias

  • Statistics: Systematic offset between the average of repeated measurements and the true or reference value.
  • Metrology: The estimated systematic offset of a measuring system: its average reading minus the reference value.

Bin

  • Tides: One depth cell of an ADCP profile, the slice of water over which a single velocity is averaged.
  • Statistics: Test category that each die or unit is sorted into at probe or final test, with bin 1 usually meaning good.

Block

  • Railroad: A group of cars bound for the same destination, kept together so they can be handled as one unit.
  • Statistics: Group of experimental runs made under similar conditions, used to remove a known nuisance source such as...

Bluing

  • Gears: Shop word for marking compound brushed on gear teeth to read the contact pattern after running.
  • Paper Optics: Mill talk for adding blue or violet dye to make a white sheet look whiter by masking its yellow cast.

Bond

  • Corrosion: Wire or cable connection that ties two metal structures together electrically, often to control CP current.
  • Electricians: Connection that ties metal parts together so they stay at one potential and give fault current a path home.

Boomer

  • Electricians: Traveling electrician or lineman who follows big projects from city to city wherever the work is.
  • Railroad: A railroader who drifts from railroad to railroad, hiring on wherever the work is good.

Boot

  • Geosynthetics: Field-built geomembrane sleeve that seals a liner around a pipe or other penetration.
  • Waterproofing: A preformed or field-built collar that seals a pipe, rod or conduit where it passes through a membrane.

Bowl

  • Nuclear: The steam generator channel head, the hemispherical space under the tubesheet where reactor coolant enters...
  • Railroad: The set of classification tracks at the bottom of a hump yard where sorted cars collect.

Breakout

  • Refractories: Escape of molten metal or slag through a failed lining and shell, the most dangerous refractory failure.
  • PCBs: Drilled hole wandering past the edge of its pad, or the routing that escapes signals from a dense part.

Bridging

  • Thermal Spray: Coating that forms a continuous skin across the edge of a mask, so it tears or lifts when the mask comes off.
  • PCBs: Solder defect in which solder joins two pads or leads that should be separate, creating a short.

Bugholes

  • Concrete: Small surface pits on vertical formed concrete left by air bubbles trapped against the form face.
  • Waterproofing: Small surface voids in formed concrete left by trapped air bubbles against the formwork.

Burn-in

  • Welding: Shop word for how deeply a bead melts into the base metal or sidewalls, especially at the root and toes.
  • Statistics: Operating products under raised stress before shipment so weak units fail in the factory instead of in the...

Burn-through

  • Welding: A hole melted through the root of a weld where the molten metal fell out.
  • Geosynthetics: Hole or severe thinning in a geomembrane where a welder ran too hot or stopped on the sheet.

Burner

  • Welding: Shop name for the tradesperson who does torch cutting, or for the cutting torch itself.
  • Boilers: The assembly that mixes fuel with air and holds a stable flame to heat the boiler.

Bust

  • Welding: Shop slang for failing a weld test or inspection, as in busting a bend or an X-ray.
  • Hydrography: A vertical or horizontal mismatch between overlapping lines or surveys that exposes an error somewhere.

Cage

  • Powder Coating: Shop shorthand for a recess resisting powder because of Faraday cage effect.
  • Valves: A slotted or drilled sleeve around a control valve plug that guides it and shapes how flow changes with...

Carbide

  • Heat Treating: Any hard compound of carbon with iron or alloying elements such as chromium, vanadium, molybdenum or tungsten.
  • Thermal Spray: Shop shorthand for a carbide coating, usually tungsten carbide, as in putting carbide on a part.

Carburizing

  • Heat Treating: Diffusing carbon into the surface of low-carbon steel at high heat, then quenching for a hard case.
  • Gears: A heat treatment that diffuses carbon into the surface of low-carbon steel gears, then quenches for a hard...

Carrier

  • Adhesives: The film, foam, paper or fabric layer inside a tape that the adhesive is coated onto.
  • Paper Optics: Water-soluble polymer such as PVOH that boosts optical brightener efficiency in coatings and size-press...

Case depth

  • Heat Treating: Thickness of a hardened surface layer, measured from the surface to a specified hardness or structure.
  • Gears: How deep the hardened surface layer of a gear tooth goes, usually measured to a set hardness such as 50 HRC.

Cert

  • Heat Treating: Shop word for the certificate of heat treatment that states what was done to a lot and the results.
  • Welding: Shop word for a welder's qualification, or the test taken to earn it, as in a 6G cert.

Chalking

  • Corrosion: Powdery residue on an aging coating surface as sunlight breaks down the binder.
  • Powder Coating: A powdery residue on a weathered finish where sunlight has broken down the resin at the surface.

Chart datum

  • Hydrography: The low-water level from which charted depths are measured, set so actual depth is seldom much less than...
  • Tides: The low-water zero that charted depths and tide table heights are measured from.

Cheater bar

  • Valves: A length of pipe slipped over a wrench or valve handle to gain extra leverage on something stuck.
  • Machine Shop: A length of pipe slipped over a wrench handle for extra leverage on a stuck fastener.

Chromatic dispersion

  • Photonics: The change of refractive index with wavelength, which separates colors in prisms and spreads pulses in time.
  • Fiber Optics: Pulse spreading caused by different wavelengths in a light source traveling at slightly different speeds in...

Control joint

  • Concrete: A planned groove or sawcut that makes a slab crack in a straight line exactly where the crew wants it.
  • Waterproofing: A cut or formed groove that makes concrete or masonry crack in a straight, planned line instead of randomly.

Cook

  • Thermal Spray: Booth slang for overheating a part during spraying, usually from slow traverse, short standoff or no pauses.
  • Powder Coating: Line slang for curing parts in the oven, and in the past tense, for parts that got too much heat.

Cure

  • Adhesives: The chemical reaction or physical change that turns a liquid adhesive into a solid that carries load.
  • Refractories: To hold freshly placed castable moist and at moderate temperature so its cement can fully hydrate.

Cut

  • Thermal Spray: Shop word for a powder's particle size range, such as minus 45 plus 15 micrometers.
  • Railroad: A group of cars coupled together and handled as one piece; as a verb, to uncouple them.

Cv

  • Valves: Flow coefficient: US gallons per minute of 60 degree F water a valve passes with a 1 psi pressure drop.
  • Nonwovens: Coefficient of variation: standard deviation divided by the mean, the yardstick of nonwoven uniformity.

Delta E

  • Powder Coating: A single number for how far a color is from its standard, read by a spectrophotometer.
  • Paper Optics: Single number for the total color difference between a sample and its target, usually in CIELAB units.

Dog bone

  • Adhesives: A cast or cut tensile specimen with wide ends and a narrow middle, used to test bulk adhesive properties.
  • PCBs: Short trace from a surface mount pad to a nearby via, shaped like a cartoon bone, used to fan out parts.

Drift

  • Statistics: Slow, steady creep of a process or gauge reading in one direction as something wears, depletes or ages.
  • Metrology: Gradual change in an instrument's readings over time that comes from the instrument itself, not from what it...

Drop

  • Fiber Optics: The final fiber cable run from a distribution terminal on the street to a single customer building.
  • Waterproofing: A vertical strip of facade worked from top to bottom on one setup of a swing stage or bosun's chair.

Drum

  • Boilers: A large cylindrical vessel in a watertube boiler where steam separates from water or where sediment collects.
  • Concrete: The rotating mixing barrel on a ready-mix truck, turning one way to mix and the other to discharge.

Dry-out

  • Refractories: Controlled first heat-up of a new monolithic lining to drive off water without cracking or spalling.
  • Tides: To let a boat settle deliberately on the bottom as the tide falls, against a wall, on legs or on twin keels.

Dutchman

  • Valves: A short filler piece of pipe cut in to close a gap or correct a misfit between two spools.
  • Waterproofing: A patch of new stone, brick or wood cut and set into a damaged area of an original piece.

Efflorescence

  • Concrete: The white powder or crust that appears where water seeps out of concrete or masonry and leaves its salts...
  • Waterproofing: White crystalline salt deposits left on masonry or concrete as water moving through it evaporates.

Expansion joint

  • Refractories: Gap deliberately left in a lining so bricks or castable can grow with heat without crushing or lifting.
  • Waterproofing: A designed gap between building elements that lets them move with temperature, settlement and load without...

FBE

  • Corrosion: Fusion-bonded epoxy: a powder coating fused onto heated pipe, the standard external line pipe coating.
  • Powder Coating: Fusion-bonded epoxy, a fast-curing epoxy powder applied to preheated pipe, rebar and valves for corrosion...

Feather

  • Welding: To grind the start, stop or tack of a weld to a thin taper so the next bead can tie in smoothly.
  • Asphalt: To taper new asphalt down to nearly zero thickness to tie it into an existing surface.

Fingernail test

  • Powder Coating: The rough floor check of cure: dig a thumbnail into a cooled part and see if it marks.
  • Gears: Shop check of dragging a fingernail across a tooth flank to judge whether surface damage has real depth.

Flag

  • Electrotechnology: Indicator on a protection relay showing which element or phase operated; also the verb for it showing.
  • Lighting: A black fabric panel on a frame used on film sets to block light from hitting part of a scene or the lens.

Flashing

  • Valves: Liquid partly turning to vapor through a valve because downstream pressure stays below its vapor pressure.
  • Waterproofing: Thin sheet metal or membrane installed at joints and interruptions in a wall or roof to direct water back...

Footprint

  • Thermal Spray: The shape of the deposit a gun leaves in a short stationary shot or single line, used to check spray...
  • PCBs: Pattern of copper pads, outline and markings on a board that matches one component package.

Frosting

  • Tribology: Shop name for the dull, satin-gray sheen of early micropitting on gear teeth or bearing races.
  • Gears: Shop word for the dull, frosted gray patches on gear teeth that turn out to be micropitting.

Fuzz

  • Gears: Shop word for the fine metallic paste that collects on a magnetic drain plug from normal gear wear.
  • Nonwovens: Loose fiber ends on the surface of a nonwoven that lift into pills or lint when rubbed.

Gate valve

  • Valves: A multi-turn isolation valve that lifts a flat or wedge-shaped gate clear of the flow path to open.
  • Vacuum: Full-bore valve with a sliding plate that isolates a high vacuum pump or a load lock from the chamber.

Ghost

  • Photonics: A weak stray beam from a back-surface reflection that travels off in an unexpected direction or focuses...
  • Fiber Optics: A false event on an OTDR trace caused by a strong reflection bouncing back and forth in the fiber.

Gloss

  • Powder Coating: How mirror-like a finish is, read with a gloss meter at a fixed angle, usually 60 degrees.
  • Paper Optics: The mirror-like shine of a paper or print surface, measured as specular reflectance at a defined angle.

Grab tensile

  • Geosynthetics: Index tensile test on geotextiles in which a 100 mm wide specimen is gripped by 25 mm jaws in its middle.
  • Nonwovens: Tensile test in which jaws narrower than the specimen grip its center, so neighboring fibers help carry the...

Green

  • Refractories: Describes refractory that has been formed or placed but not yet fired, dried or heated in service.
  • Gears: Shop word for a gear in its soft, machined state before heat treatment, as in cut green, finish hard.

Ground

  • Powder Coating: The electrical path from the part through hooks, racks and conveyor to earth that lets charged powder stick.
  • Welding: Shop word for the work lead and its clamp, which completes the welding circuit through the part.

Gun

  • Thermal Spray: Booth word for the thermal spray torch itself, whether plasma, HVOF, arc or flame.
  • Geosynthetics: Installer slang for the hand-held extrusion welder used on patches, boots and detail welds.

Hang

  • Powder Coating: To load parts onto hooks or racks at the start of the line.
  • Hydrography: In a wire drag sweep, the moment the wire catches on an obstruction, and the obstruction that caused it.

Home run

  • Electricians: Part of a circuit running from the first box back to the panel, or the arrow on a drawing that shows it.
  • Fiber Optics: A dedicated fiber run straight from the central point to one end location, with no splitter or shared path...

Hot box

  • Asphalt: A heated, insulated hopper on a truck or trailer that keeps mix hot all day for patching.
  • Railroad: An overheated wheel bearing on a railcar, a defect that can burn the end off an axle if missed.

Hunting

  • Valves: A control valve or loop swinging back and forth around setpoint instead of settling.
  • HVAC: A TXV or control swinging back and forth, alternately overfeeding and starving the evaporator instead of...

Hydration

  • Refractories: Reaction of magnesia or lime in a refractory with water or humidity, causing swelling, cracking and dusting.
  • Concrete: The heat-releasing reaction of cement with water that turns the paste into solid binder.

Hydro

  • Valves: A hydrostatic pressure test: filling a valve, piping system or vessel with water and pressurizing it to...
  • Hydrography: Clipped insider word for hydrography, hydrographic surveying, or the survey team itself.

Induction hardening

  • Heat Treating: Heating only the surface of a steel part with an alternating magnetic field, then quenching for a hard case.
  • Gears: Hardening gear teeth by heating them locally with an induction coil and quenching immediately.

Integrating sphere

  • Lighting: A white-lined hollow ball that spreads a source's light evenly so one detector can read its total lumens and...
  • Paper Optics: Hollow sphere lined with a highly reflective matte white that bathes a sample in diffuse light from all...

Jo blocks

  • Machine Shop: Shop name for gauge blocks: lapped steel or ceramic blocks, accurate to millionths, stacked to make any...
  • Metrology: Shop name for gauge blocks, precision steel or ceramic blocks wrung together to build reference lengths.

Jumper

  • Nuclear: A worker who makes brief entries into very high radiation spaces, absorbing a large dose allowance in minutes.
  • Fiber Optics: A short fiber cable with connectors on both ends, used to patch equipment to panels or panels to each other.

Kicker

  • Electricians: Single shallow bend that angles conduit off its line, for example to bring it out from a wall into equipment.
  • Railroad: A car whose brake valve throws the whole train into emergency when only a normal service application was made.

Laitance

  • Concrete: The soft, chalky skin of fines that bleed water leaves on top of concrete, too weak to bond to.
  • Waterproofing: A weak, powdery skin of cement and fines on the surface of concrete that sealants and membranes cannot hold...

Lambda ratio

  • Tribology: Oil film thickness divided by the combined roughness of the two surfaces, used to judge the lubrication...
  • Gears: Oil film thickness divided by combined surface roughness, showing how well the lubricant separates the teeth.

Land

  • Welding: Shop word for the flat root face left at the bottom of a bevel, called the root face in codes.
  • Electricians: To terminate a conductor on a breaker, lug, terminal or device.

Light off

  • Thermal Spray: To ignite the spray gun, whether striking a plasma arc or lighting an HVOF or flame torch.
  • Boilers: The moment a burner ignites, and also the verb for lighting it.

Magic smoke

  • Machine Shop: Joke that electrical parts run on smoke sealed inside them, because once it gets out they stop working.
  • Electrotechnology: Joking name for the smoke a burnt-out component releases, as if the smoke were what made it work.

Make up

  • Valves: To screw a threaded joint together and tighten it, or to assemble and torque a flanged joint.
  • Electricians: To splice, pigtail and fold the wires in a box so it is ready for a device or cover.

Masking

  • Thermal Spray: Covering areas of a part that must not be blasted or coated, using tapes, plugs, shields or maskants.
  • Powder Coating: Protecting threads, holes and contact surfaces from powder with heat-resistant tape, caps and plugs.

Megger

  • Electrotechnology: To test insulation resistance with a high-voltage DC tester; also the jobsite name for the tester itself.
  • Electricians: Insulation resistance tester, and the verb for testing a cable or motor with one.

Metamerism

  • Lighting: The effect where two colors match under one light source but not under another, because their spectra differ.
  • Paper Optics: Two samples matching in color under one light but not under another, because their reflectance curves differ.

MIC

  • Corrosion: Microbiologically influenced corrosion: corrosion started or sped up by bacteria and other microbes.
  • Machine Shop: Short for micrometer, pronounced mike, and the verb for measuring a part with one.

Microhardness

  • Heat Treating: Hardness measured with very small loads under a microscope, used for thin cases and individual phases.
  • Thermal Spray: Hardness of a coating measured with tiny diamond indents on a polished cross section.

Micropitting

  • Tribology: Fatigue damage made of tiny pits, about 10 to 20 microns deep, that turns gear and bearing surfaces dull gray.
  • Gears: Very fine surface fatigue pits, too small to see one by one, that give tooth flanks a dull gray look.

Module

  • Refractories: Block of folded or stacked fiber blanket, compressed and fitted with anchor hardware for fast furnace lining.
  • Gears: The metric measure of gear tooth size: pitch diameter in millimeters divided by the number of teeth.

Moly

  • Tribology: Shop name for molybdenum disulfide, the black solid lubricant, or for any grease that contains it.
  • Thermal Spray: Shop name for sprayed molybdenum, a scuff-resistant coating for piston rings, synchro rings and bond coats.

Mud cracking

  • Corrosion: Network of cracks like dried mud in a coating applied too thick, typical of inorganic zinc and waterborne...
  • Thermal Spray: A network of surface cracks that looks like dried mud, from tensile stress in a coating.

Mule tape

  • Electricians: Flat woven polyester pulling tape printed with footage marks, used for long pulls and to measure runs.
  • Fiber Optics: Flat, low-stretch polyester pull tape with printed footage marks, left in conduit to pull cable later.

Nipple

  • Valves: A short length of pipe, threaded or plain on its ends, used to connect two fittings or a valve to a fitting.
  • Electricians: Short length of conduit, threaded or with fittings on both ends, connecting two nearby boxes or enclosures.

Nitriding

  • Heat Treating: Diffusing nitrogen into steel below its critical temperature to form a hard case with no quench.
  • Gears: A low-temperature surface hardening that diffuses nitrogen into alloy steel gears with almost no distortion.

Normal distribution

  • Statistics: Symmetric bell-shaped distribution set by a mean and a standard deviation, the default model for measurement...
  • Metrology: The bell-shaped distribution assumed for most certificate values and averaged readings, set by mean and...

Nozzle

  • Thermal Spray: In a plasma gun, the water-cooled copper anode the arc attaches to; in HVOF, the passage that shapes the jet.
  • Boilers: The precision tip on an oil burner that atomizes oil into a fine cone-shaped spray, rated in gallons per hour.

Nuisance trip

  • Electrotechnology: Protective device opening with no real fault present, usually from bad settings, leakage or transients.
  • Boilers: A safety shutdown or lockout caused by a faulty or marginal device, not by a real unsafe condition.

Offset

  • Electricians: Two equal bends in opposite directions that shift a conduit run sideways to clear an obstruction or enter a...
  • Metrology: A constant error that shifts every reading by the same amount, most often seen as a nonzero reading at zero...

Overlap

  • Geosynthetics: Width by which neighboring rolls of geotextile, geogrid or GCL lie over one another to keep a continuous...
  • Hydrography: The share of each swath that is also covered by the neighbouring line, planned in to guard against gaps.

Oxygen scavenger

  • Corrosion: Chemical that strips dissolved oxygen from water to stop oxygen pitting in boilers and injection systems.
  • Boilers: A chemical fed to boiler feedwater that reacts with and removes the last traces of dissolved oxygen.

Pad

  • PCBs: Exposed copper area on a board where a component lead or terminal is soldered.
  • Paper Optics: Lab talk for a stack of sheets thick enough to be opaque, used for R-infinity, brightness and color readings.

Pass

  • Thermal Spray: One sweep of the gun across the area being coated; the coating is built up pass by pass.
  • Boilers: One run of combustion gases from end to end through a boiler before they turn or leave.

Patch

  • Fiber Optics: To connect two ports, usually equipment to panel or panel to panel, with a jumper.
  • Geosynthetics: Piece of geomembrane extrusion-welded over a hole, defect, destructive sample cut-out or failed seam section.

PCE

  • Refractories: Pyrometric cone equivalent: a refractory's softening point expressed as the number of a matching standard...
  • Nuclear: Personnel contamination event: contamination found on a worker's skin or personal clothing above a set...

Peel-and-stick

  • Adhesives: Describing any product with a ready-coated pressure-sensitive adhesive under a liner that goes on without...
  • Waterproofing: Field name for self-adhered membrane: rubberized asphalt or butyl sheet with a release liner on the back.

Persuader

  • Machine Shop: Shop name for a hammer, usually a big one, used to convince a stuck part to move.
  • Electricians: Joking name for a hammer or big pry bar, the tool used when something needs convincing to fit.

Pinhole

  • Powder Coating: A tiny hole running through the cured film, often down to bare metal.
  • Nonwovens: Tiny hole in a barrier fabric or film that lets liquid or particles through.

Pitch

  • Fasteners: The distance from one thread crest to the next, measured parallel to the screw axis.
  • Hydrography: Bow-up or bow-down rotation of a vessel, which shifts sonar footprints forward or aft along the track.

Pitch diameter

  • Fasteners: The diameter at which thread thickness equals the gap between threads, the dimension that controls fit.
  • Gears: The diameter of the pitch circle, the imaginary rolling circle on which tooth size and gear ratio are based.

Plug

  • Concrete: A blockage that jams a concrete pump line or hose, stopping placement until it is cleared.
  • Railroad: A short piece of rail cut into the track to replace a section with a defect or a break.

Plume

  • Thermal Spray: The visible jet of hot gas and glowing particles streaming from the spray gun toward the part.
  • Nuclear: The cloud of radioactive gases and particles carried downwind from a release.

Pop-off

  • Adhesives: A part that lets go with a snap, leaving the adhesive cleanly on one side and nothing on the other.
  • Boilers: Shop slang for the safety valve on a steam boiler or the relief valve on a hot water boiler.

Porosity

  • Thermal Spray: The fraction of a coating's volume made of voids between and within splats, usually reported in percent.
  • Welding: Gas bubbles trapped in weld metal as it freezes, showing as round holes on the surface or on film.

Pot life

  • Corrosion: Working time after mixing a two-part coating before it has reacted too far to apply properly.
  • Adhesives: How long a mixed batch of two-part adhesive stays usable before it thickens too much to apply.

Power

  • Railroad: The locomotives assigned to a train, or locomotives in general.
  • Statistics: Probability that a test will detect a real effect of a given size, set by sample size, noise and alpha.

PPK

  • Hydrography: Post-processed kinematic: GNSS positions computed after the survey from logged rover and base data, at...
  • Statistics: Process performance index: a Cpk-style figure computed with the overall standard deviation, capturing...

Preheat

  • Thermal Spray: Warming the substrate before spraying to drive off moisture and reduce stress at the coating interface.
  • Welding: Heating base metal before welding to slow cooling and drive off moisture, preventing hydrogen cracks.

Primer

  • Adhesives: A thin first coat wiped or sprayed onto a bonding surface so the adhesive grips better or the fresh prep...
  • Waterproofing: A thin liquid brushed or wiped onto a joint face or deck so the sealant or membrane bonds reliably.

PSA

  • Adhesives: Pressure-sensitive adhesive, the always-tacky layer on tapes and labels that bonds under finger pressure...
  • Nuclear: Probabilistic safety assessment: a systematic model of how accidents could happen and how likely each...

PT

  • Welding: Penetrant testing: revealing surface-breaking cracks by drawing colored or fluorescent dye out of them.
  • Concrete: Post-tensioning: reinforcing concrete with steel tendons that are stretched tight after the concrete hardens.

Pump down

  • HVAC: Moving a system's refrigerant into the condenser or receiver by shutting the liquid line and running the...
  • Vacuum: To evacuate a chamber from atmosphere to its working pressure, through roughing, crossover and high vacuum.

Quench

  • Heat Treating: To cool hot metal rapidly in a liquid or gas so that it hardens, or the act of doing so.
  • Nonwovens: Stream of cooled, conditioned air that solidifies filaments just below the spinneret in spunbond and fiber...

Recovery

  • HVAC: Removing refrigerant from a system into a recovery cylinder instead of venting it to the atmosphere.
  • Tides: Finding an existing bench mark in the field, checking its condition and reporting it as found, damaged or...

Red tag

  • Electricians: Failed inspection notice, or the act of an inspector failing work so it must be fixed and reinspected.
  • Metrology: A reject tag marking an instrument as unfit for use, or the act of pulling one from service with it.

Reference standard

  • Paper Optics: Certified material with assigned reflectance values that transfers a measurement scale to a working...
  • Metrology: A lab's highest-level standard for a quantity, used only to calibrate other standards and never for routine...

Regen

  • Photonics: Clipped form of regenerative amplifier, the cavity that traps a seed pulse for many passes of gain before...
  • Vacuum: Clipped form of regeneration: warming a cryopump to drive off the gas it has captured, then cooling it again.

Relief valve

  • Valves: A spring-loaded valve for liquid service that opens gradually as pressure rises past its set point.
  • Boilers: The pressure-relief valve on a hot water boiler, rated in Btu per hour and set at or below the boiler's...

Repeatability

  • Statistics: Scatter in the readings when one person and one gauge measure the same part over and over with nothing else...
  • Metrology: How tightly readings bunch when one person repeats a measurement with the same setup, in one place, in one...

Reproducibility

  • Statistics: Variation in measurement results when different operators, gauges or setups measure the same items.
  • Metrology: How well results on the same item agree when the lab, operator, equipment or day is changed on purpose.

Residual

  • Tides: The observed water level minus the predicted tide, showing the effect of weather, rivers and other non-tidal...
  • Statistics: Difference between an observed value and the value a fitted model predicts for it.

Resolution

  • Statistics: Rating of a fractional factorial design, in Roman numerals, that states which effects are aliased with which.
  • Metrology: The finest step an instrument can display, such as one count of the last digit on a digital readout.

Rod

  • Welding: Shop word for a stick welding electrode, as in burning rod or a box of 7018 rod.
  • Fiber Optics: To push a stiff fiberglass duct rodder through a conduit to prove the path or to carry a pull line through.

Roll

  • Fiber Optics: To swap the two fibers of a duplex pair so transmit and receive line up with the far end.
  • Hydrography: Rotation of a vessel about its fore-and-aft axis, measured to correct the angle of every sonar beam.

RSS

  • Geosynthetics: Reinforced soil slope: an embankment built steeper than its fill could stand alone by layering geogrid or...
  • Metrology: Root sum of squares, combining independent uncertainty contributions by squaring, adding and taking the...

Run-in

  • Gears: Operating new gears at reduced load at first so surface high spots wear smooth before full duty.
  • Hydrography: The stretch before a survey line where the boat settles on course and speed before logging starts.

Running hot

  • Tribology: Shop phrase for a bearing, gearbox or motor operating above its normal temperature.
  • Thermal Spray: Booth talk for parameters that are overheating the particles or part; running cold is the opposite.

Running rich

  • Heat Treating: Shop talk for a furnace atmosphere carrying more carbon than its setpoint and heading toward soot.
  • Boilers: Burning with too much fuel for the air available, so combustion is incomplete.

Runout

  • Gears: How much the teeth wobble radially relative to the gear's axis, measured with a probe in each tooth space.
  • Geosynthetics: Flat length of geosynthetic between the crest of a slope and the anchor trench.

Safety valve

  • Valves: A spring-loaded pressure relief valve for steam, gas or vapor that opens with a rapid full lift at set...
  • Boilers: The spring-loaded valve on a steam boiler that pops fully open to vent steam before pressure exceeds the...

Sag

  • Adhesives: An adhesive bead slumping or running down a vertical or overhead surface before it sets.
  • Electrotechnology: Brief drop in RMS supply voltage, usually to between 10 and 90 percent of nominal, lasting up to about a...

Scale

  • Heat Treating: The oxide crust that forms on steel heated in air or in an oxidizing atmosphere.
  • Boilers: A hard mineral crust that forms on boiler heat transfer surfaces from calcium, magnesium and silica in the...

Scallops

  • Gears: Shop word for the small ridges a hob leaves across and along each tooth flank, visible as a fine texture.
  • Lighting: The arched pattern of light and shadow that downlights draw on a wall when mounted close to it.

SCC

  • Corrosion: Stress corrosion cracking: brittle cracking caused by tensile stress acting together with a specific...
  • Concrete: Self-consolidating concrete, a highly fluid mix that fills forms and wraps rebar under its own weight.

Screed

  • Concrete: To strike off fresh concrete to the right height, or the straightedge, board or machine that does it.
  • Asphalt: The heated, floating plate assembly at the back of a paver that levels and pre-compacts the mat.

Scuffing

  • Tribology: Sudden, severe adhesive damage where the oil film fails and sliding surfaces locally weld and tear.
  • Gears: Sudden adhesive damage where tooth surfaces weld and tear apart because the oil film broke down.

Segregation

  • Concrete: Separation of coarse aggregate from the mortar in fresh concrete, leaving rock-heavy and paste-heavy zones.
  • Asphalt: Separation of coarse and fine aggregate, or of hot and cold mix, that leaves open, low-density spots in the...

Sheet

  • Paper Optics: Papermakers' word for the continuous paper web on the machine, and for the grade as a product.
  • Hydrography: Crew shorthand for one registered survey area and its data set, worked and reported as a single unit.

Shelf life

  • Powder Coating: How long boxed powder stays sprayable and reactive when stored cool and dry.
  • Adhesives: The use-by window for a sealed container of adhesive, tied to the storage conditions on the label.

Short cycling

  • HVAC: A compressor or system turning on and off too often, with run times too short to reach steady operation.
  • Boilers: A burner starting and stopping far too often, with short run times that waste fuel and wear parts.

Shotcrete

  • Refractories: Wet-mix gunning: castable pumped through a hose and set instantly by accelerator added at the nozzle.
  • Concrete: Concrete shot from a nozzle by compressed air and built up in layers on walls, slopes, pools and tunnels.

Soak

  • Heat Treating: To hold parts at a set temperature until they are evenly heated and the intended change is complete.
  • Metrology: Letting an instrument, artifact or part sit in the lab environment until it reaches thermal equilibrium.

Sock

  • Fiber Optics: A woven wire mesh pulling grip that slips over a cable end and tightens as it is pulled.
  • Geosynthetics: Knitted or nonwoven geotextile sleeve slipped over perforated drainpipe to keep soil out of the slots.

Soup

  • Tribology: Grease that has broken down or been mixed with an incompatible type and turned runny.
  • Concrete: Concrete so wet it runs like liquid, usually because too much water went into the truck.

Split

  • Refractories: Brick of standard length and width but reduced thickness, used to adjust course heights.
  • HVAC: The temperature difference between return and supply air across a coil, used as a quick health check.

Squeeze-out

  • Adhesives: The excess adhesive that oozes out along the joint edges at clamp-up, read as proof the joint is full.
  • Geosynthetics: Bead of molten polymer pressed out along the edge of a fusion seam by the welder's rollers.

Standard deviation

  • Statistics: Typical distance of individual values from their mean, the basic measure of spread, written as sigma or s.
  • Metrology: The usual measure of scatter in a set of values, the square root of the average squared deviation from the...

Strike-through

  • Paper Optics: Penetration of ink or its oil vehicle through a sheet far enough to darken or stain the reverse side.
  • Nonwovens: Hygiene test time for a set dose of liquid to pass through a topsheet into the absorbent pad underneath.

Strip

  • Powder Coating: To remove cured powder from a rejected part or rack so it can be recoated.
  • Nonwovens: Line name for the thin perforated metal jet strip that forms the water jets in a hydroentangling injector.

Substrate failure

  • Adhesives: A joint failure where the bonded material itself breaks before the adhesive or the interface gives.
  • Waterproofing: The joint face itself breaking, so sealant comes away with a skin of concrete, coating or EIFS still attached.

Tackifier

  • Tribology: Polymer additive that makes a lubricant sticky and stringy so it clings to chains, open gears and slides.
  • Adhesives: A resin added to rubber or acrylic adhesives to raise their tack and peel.

Tg

  • Adhesives: Glass transition temperature, above which a cured adhesive turns from hard and glassy to soft and rubbery.
  • PCBs: Glass transition temperature: the point where a board's resin turns from rigid to rubbery and expands much...

Threadlocker

  • Adhesives: An anaerobic adhesive applied to fastener threads to stop them loosening from vibration.
  • Fasteners: An anaerobic adhesive applied to threads that hardens between metal surfaces to stop loosening and seal.

Throat

  • Welding: The thinnest section through a fillet weld, from the joint root to the face, which sets how much load it...
  • Vacuum: Inlet opening of a high vacuum pump, the flange where gas enters a turbo, cryo or diffusion pump.

Throw

  • HVAC: How far a supply air jet reaches into a room before it slows to a chosen speed, such as 50 feet per minute.
  • Lighting: The distance from a lighting fixture to the surface or subject it lights, which sets beam size and intensity.

Tie-in

  • Welding: How well a weld fuses into the base metal, the bead beside it, or the end of an earlier weld.
  • Geosynthetics: Connection that joins a new liner to an existing one, as when a landfill cell is expanded.

Tolerance

  • Machine Shop: The total amount a dimension is allowed to vary from nominal and still be a good part.
  • Metrology: The allowed deviation from nominal that an item or instrument may show and still be accepted.

Tooth

  • Corrosion: Painters' word for the roughness on a surface that gives a coating something to grip.
  • Thermal Spray: Shop word for the bite or roughness left on a blasted surface, the grip a coating needs to hold on.

Top off

  • Tribology: To add oil to bring a gearbox, sump or reservoir back up to its correct level.
  • HVAC: To add refrigerant to a system that is low on charge without finding and fixing the leak.

Traveler

  • Heat Treating: The paperwork that rides with a lot through the shop, recording each operation, furnace, time and result.
  • Electricians: One of the two conductors run between three-way switches, carrying power on whichever path is selected.

Varnish

  • Tribology: Thin, sticky, amber-to-brown deposit from degraded oil that coats valves, bearings and coolers.
  • Railroad: Freight crew slang for a passenger train, after the glossy varnished finish of wooden coaches.

VT

  • Welding: Visual testing: inspecting welds by eye with gauges, lights and magnifiers, the first and most-used NDE...
  • Electrotechnology: Voltage transformer: an instrument transformer that steps high voltage down to a standard level for relays...

Wash

  • Powder Coating: Line slang for the spray pretreatment washer, or for the pass a part makes through it.
  • Lighting: Broad, even light covering a whole stage area or surface, built from overlapping soft-edged fixtures.

Wedge

  • Valves: The tapered closure member of a gate valve that is driven down between two inclined seats to seal.
  • Geosynthetics: Installer shorthand for the hot wedge welder, or for the heated wedge inside it.

Weep

  • Tribology: To leak very slowly, leaving a damp oil film around a seal or joint rather than actual drips.
  • Waterproofing: An opening at the base of a wall or window system that lets collected water drain out.

Wet

  • Heat Treating: Shop word for a furnace atmosphere with too much water vapor, meaning a high dew point and low carbon.
  • Vacuum: Said of a chamber whose walls still hold adsorbed water, so it pumps down slowly and stalls high.

Wet end

  • Paper Optics: Front section of a paper machine, where stock is formed into a sheet and most of the water is drained and...
  • Hydrography: The underwater parts of a survey system, such as the sonar head or towfish, as opposed to the topside...

Wet-out

  • Adhesives: How fully a tape's adhesive has flowed into contact with a surface, often visible through clear parts.
  • Nonwovens: Line and lab talk for how readily a fabric lets liquid soak in and spread instead of beading on top.

Wetting

  • Adhesives: How well a liquid adhesive spreads over and makes intimate contact with a surface.
  • Welding: Molten filler spreading across a clean surface and bonding to it, needed for a sound braze or solder.

Wrap

  • Powder Coating: Charged powder curling around edges onto the back of a part that the gun never pointed at.
  • Nonwovens: Fibers or web winding around a roll instead of passing through, which can stop a line or damage the roll.

Zinc-rich primer

  • Corrosion: Primer loaded with zinc dust that protects steel galvanically as well as acting as a barrier.
  • Powder Coating: Epoxy powder primer loaded with zinc dust to give steel extra corrosion protection under a topcoat.

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