Insiders LingoThe words the pros use
A to Z

Terms starting with B

287 entries starting with the letter B, across every field.

  • b*Paper Optics
    Yellow-blue coordinate in CIELAB, positive toward yellow and negative toward blue, watched closely on white papers.
  • B7Fasteners
    The chromium-molybdenum alloy stud grade that is the default for pipe flange and pressure vessel bolting.
  • BabbittTribology
    Soft tin- or lead-based alloy that lines plain bearings so they tolerate dirt and brief contact.
  • BabysitMachine Shop
    To stand and watch a machine run a job because it cannot yet be trusted to run on its own. Shop talk
  • Back-drillingPCBs
    Drilling out the unused stub of a plated through via from the far side so it does not disturb fast signals.
  • Back ionizationPowder Coating
    Tiny electrical discharges inside an overcharged powder layer that repel new powder and pit the finish.
  • Back tenderPaper Optics
    Paper machine crew member who runs the dry end, handling reels, samples and threading the sheet. Shop talk
  • Back-to-backElectricians
    Bend layout that sets the outside distance between the backs of two 90-degree bends in one piece of conduit.
  • Backer rodWaterproofing
    A round foam cord pushed into a joint to set sealant depth and keep the sealant from bonding to the back.
  • BackfeedElectrotechnology
    Power arriving at a circuit from an unexpected direction, such as a generator or second supply feeding back. Shop talk
  • BackfillVacuum
    To fill an evacuated chamber with a chosen gas, often to a set pressure, rather than with room air.
  • BackgroundNuclear
    The ever-present radiation from natural and other sources that an instrument reads when no source of interest is near.
  • Backhoe fadeFiber Optics
    Joking term for a fiber outage caused by an excavator digging through buried cable. Shop talk
  • Backing pumpVacuum
    Pump that keeps the exhaust of a turbo, diffusion or Roots pump below its maximum allowed pressure.
  • BacklashGears
    The play between mating teeth: how far one gear can rock before its teeth contact the other gear's teeth.
  • BackscatterFiber Optics
    The small fraction of light scattered in the fiber that travels back toward the source, which OTDRs measure.
  • BackscatterHydrography
    The strength of sound returned from the seabed, used to map bottom type alongside depth.
  • BackseatValves
    A seat on the underside of the bonnet that a stem shoulder seals against at full open, isolating the packing.
  • BacksheetNonwovens
    Outer, liquid-proof layer of a diaper or pad, usually breathable film laminated to a soft nonwoven.
  • BackstreamVacuum
    Of pump oil or vapour, to flow the wrong way, from the pump back toward the chamber. Shop talk
  • Bad groundPowder Coating
    A hook or rack contact too crusted with cured powder to carry charge away, so powder will not stick properly. Shop talk
  • Bad orderRailroad
    A car or locomotive with a defect that keeps it from running until it is repaired. Shop talk
  • BagBoilers
    A local bulge in a boiler tube, furnace or shell plate where overheated metal has been pushed out by pressure.
  • BaggingVacuum
    Enclosing a part or flange in a plastic bag filled with helium to check its overall tightness in one shot. Shop talk
  • BaghouseAsphalt
    The fabric-filter dust collector that cleans the exhaust from an asphalt plant's dryer.
  • Bail offRailroad
    To release the locomotive's own brakes during an automatic application so that only the cars do the braking. Shop talk
  • BainiteHeat Treating
    A tough mix of ferrite and fine carbides that forms between the pearlite and martensite temperature ranges.
  • BakeFasteners
    To heat plated high-strength fasteners soon after plating so absorbed hydrogen escapes before it cracks them.
  • BakePCBs
    To heat bare boards or moisture-sensitive parts in an oven to drive out absorbed water before soldering. Shop talk
  • Bake-outThermal Spray
    Heating oily or porous parts before blasting to drive out absorbed oil that would ruin the bond.
  • Bake-outVacuum
    Heating a vacuum system while pumping to drive off water and other adsorbed gas and lower the base pressure.
  • Ball-in-hand testRefractories
    Quick field check of castable water content: squeeze a ball of mix, toss it, and see whether it holds. Shop talk
  • Ball valveValves
    A quarter-turn valve that opens and closes by rotating a ball with a bore through it.
  • BallastLighting
    The device that starts and limits current to fluorescent and HID lamps, which would otherwise draw unlimited current.
  • BallastRailroad
    The bed of crushed rock under and around the ties that holds the track in line and drains water away.
  • Band-aidWaterproofing
    A bridge joint applied over an existing sealant joint as a repair, without removing the old material. Shop talk
  • Bar checkHydrography
    A singlebeam calibration that hangs a plate on marked lines under the transducer and compares the sounder with each known depth.
  • BarbNonwovens
    Small notch cut into the working blade of a felting needle that catches fibers and carries them through the batt.
  • Barometric damperBoilers
    A weighted swinging gate on the flue pipe that lets room air in to hold chimney draft steady.
  • BarrelFiber Optics
    Installer slang for a fiber adapter, the double-ended bulkhead part that joins two connectors. Shop talk
  • BarrelHVAC
    Shop name for a chiller's shell-and-tube evaporator or condenser vessel. Shop talk
  • BarrelThermal Spray
    The long tube on an HVOF or detonation gun where particles are heated and accelerated before exiting.
  • Base circleGears
    The circle from which the involute tooth profile is unwound, smaller than the pitch circle.
  • Base oil groupTribology
    Five-group system that sorts base stocks by saturates, sulfur, viscosity index and chemical type.
  • Base pressureVacuum
    The lowest pressure a particular chamber reaches after pumping for a set time with no process gas flowing.
  • Basic refractoryRefractories
    Refractory based on magnesia, lime or dolomite that resists basic slags with high lime-to-silica ratios.
  • Basis weightNonwovens
    Mass of a nonwoven per unit area, almost always given in grams per square meter.
  • Basis weightPaper Optics
    Weight of a 500-sheet ream cut to a grade's basic sheet size, used in North American paper trade.
  • Batch plantAsphalt
    An asphalt plant that weighs and mixes each load in separate batches in a pugmill.
  • Batch ticketConcrete
    The delivery ticket that travels with every ready-mix truck, showing mix, quantity, time batched and water allowed.
  • BathtubWaterproofing
    A fully wrapped below-grade waterproofing system that encloses the foundation like a tub. Shop talk
  • Bathtub curveStatistics
    Plot of failure rate over a product's life: falling early failures, a flat random period, then rising wear-out.
  • BathtubbingGeosynthetics
    Water or leachate collecting inside a lined area because more gets in from above than can drain out below. Shop talk
  • BathyHydrography
    Clipped form of bathymetry, used for depth data, depth surfaces or the depth-measuring part of a job. Shop talk
  • BathymetryHydrography
    The measured depth and shape of the seabed, or the work of measuring it.
  • BattNonwovens
    Thick layer of fibers built up from several webs, usually by cross-lapping, ready for needling or thermal bonding.
  • BattleshipElectricians
    Thin metal F-shaped clip that holds a cut-in box in drywall by gripping the back of the wall. Shop talk
  • Bayard-Alpert gaugeVacuum
    Hot cathode ionization gauge with a fine central collector wire, the standard gauge for high and ultra-high vacuum.
  • BBRAsphalt
    Bending beam rheometer: the test that checks how stiff and brittle a binder gets at low temperature.
  • BeadAdhesives
    A continuous line of adhesive laid on a part, specified by its diameter or cross-section.
  • BeamNonwovens
    Line talk for one spinning or meltblown station across the width of a spunmelt line. Shop talk
  • Beam angleLighting
    The angle across a light's beam at which intensity has fallen to 50 percent of its center value.
  • Beam dumpPhotonics
    A device that absorbs an unwanted or terminated laser beam completely and safely, without reflecting it.
  • Beam expanderPhotonics
    A pair of lenses arranged as a telescope that enlarges a collimated beam's diameter and cuts its divergence.
  • Beam profilerPhotonics
    An instrument, usually a camera or scanning slit, that measures a laser beam's intensity distribution and width.
  • Beam waistPhotonics
    The narrowest point of a focused or propagating laser beam, where its wavefront is flat.
  • BeaneryRailroad
    A cheap restaurant or lunch counter near a terminal or depot where railroaders eat. Shop talk
  • BecquerelNuclear
    The SI unit of radioactivity, equal to one atomic decay per second.
  • Bed of nailsPCBs
    Test fixture with an array of spring-loaded pins that touch every test point on a board at once. Shop talk
  • Beer can coldHVAC
    A rough feel test: the suction line should be about as cold and sweaty as a can just out of the fridge. Shop talk
  • Bell boxElectricians
    Weatherproof cast-aluminium box with threaded hubs, used for outdoor switches, receptacles and lights. Shop talk
  • Bell holeCorrosion
    Excavation dug around a short section of buried pipe so crews can inspect, repair or connect to it. Shop talk
  • Belleville washerFasteners
    A dished, conical spring washer that flattens under load and keeps clamp force on a joint as it settles or expands.
  • BellowsVacuum
    Thin, pleated metal tube that lets a vacuum joint flex or move while staying leak-tight.
  • Belly bandHVAC
    An adjustable strap mount that clamps around the body of a replacement motor so it fits many different brackets. Shop talk
  • Belly dumpAsphalt
    A trailer that unloads mix through gates in its floor, laying it in a row on the road ahead of the paver. Shop talk
  • Belt and suspendersMachine Shop
    Using two independent safeguards where one should do, for redundancy or out of extra caution. Shop talk
  • Bench markTides
    A permanent, stable mark of known height near a tide station that preserves the station's datums.
  • Bench setValves
    The air pressure range over which a spring-and-diaphragm actuator strokes the valve with no process pressure acting.
  • Bend-insensitive fiberFiber Optics
    Fiber designed to lose very little light when bent tightly, used in drops, apartment wiring and dense patching.
  • Bend radiusFiber Optics
    The tightest curve a fiber or cable can take without extra loss or damage, stated separately for pulling and at rest.
  • Bend testWelding
    Bending a strip cut from a test weld into a U to open up lack of fusion, cracks and other flaws.
  • Bending stressGears
    The tensile stress in the root fillet of a loaded tooth, which decides whether teeth break off.
  • BentoniteWaterproofing
    A sodium clay that swells into a watertight gel when wet, used in panels, mats and strips for below-grade waterproofing.
  • BevelWelding
    An angled edge prepared on a plate or pipe end so a groove weld can reach the root.
  • Bevel gearGears
    A cone-shaped gear that transmits motion between intersecting shafts, usually at right angles.
  • Beyond design basis accidentNuclear
    An accident more severe than those the plant's safety systems were explicitly designed to handle.
  • BFENonwovens
    Bacterial filtration efficiency: the percentage of a bacteria-laden aerosol that a mask or filter fabric stops.
  • BFVValves
    Butterfly valve: the clipped form used on valve tags, takeoff sheets and HVAC and fire protection drawings. Shop talk
  • BiasMetrology
    The estimated systematic offset of a measuring system: its average reading minus the reference value.
  • BiasStatistics
    Systematic offset between the average of repeated measurements and the true or reference value.
  • Biaxial geogridGeosynthetics
    Geogrid with similar strength in both directions, used mainly to stabilize aggregate bases over soft ground.
  • BibleElectricians
    Shop name for the electrical code book, the reference every electrician carries and argues from. Shop talk
  • BicoNonwovens
    Shop clip for bicomponent fiber, usually meaning sheath-core binder fiber bought for thermal bonding. Shop talk
  • Bicomponent fiberNonwovens
    Fiber spun from two different polymers in one cross section, such as a low-melting sheath around a strong core.
  • Bidirectional averagingFiber Optics
    Testing a fiber with an OTDR from both ends and averaging the results to get true splice losses.
  • Big holeRailroad
    The emergency position of the automatic brake valve, which vents the brake pipe and stops the train as fast as possible. Shop talk
  • Big hookRailroad
    The wrecking crane sent to clear a derailment and lift cars back onto the track. Shop talk
  • BILElectrotechnology
    Basic lightning impulse insulation level: the peak impulse voltage equipment must withstand without breakdown.
  • BinStatistics
    Test category that each die or unit is sorted into at probe or final test, with bin 1 usually meaning good.
  • BinTides
    One depth cell of an ADCP profile, the slice of water over which a single velocity is averaged.
  • Binder courseAsphalt
    The intermediate pavement layer placed between the base course and the surface course.
  • Binder fiberNonwovens
    Low-melting fiber blended into a web so that, when heated, it softens and glues the other fibers together.
  • BinningLighting
    Sorting LEDs after manufacture into groups with matching color, brightness and voltage.
  • BioassayNuclear
    Measurement of radioactive material inside the body, or in excreta, to estimate a worker's internal dose.
  • Bird bathConcrete
    A low spot in a finished slab or pavement where water collects and sits after rain or washing. Shop talk
  • Bird poopWelding
    Slang for an ugly, lumpy, poorly fused weld that looks like droppings sitting on the metal. Shop talk
  • Bird's nestMachine Shop
    A tangled wad of long, stringy chips wrapped around the tool, chuck or part on a lathe. Shop talk
  • BirdbathAsphalt
    A low spot in finished pavement that holds a puddle of water after rain. Shop talk
  • Black beautyCorrosion
    Genericized name for black coal slag abrasive used in open blasting of steel. Shop talk
  • Black cavityPaper Optics
    Light trap placed behind a single sheet so nothing reflects back from the backing during an R0 reading.
  • Black lightPaper Optics
    Handheld or bench UV lamp used to check quickly whether a paper contains optical brightener. Shop talk
  • Black padPCBs
    ENIG defect where corroded nickel under the gold produces dark, brittle solder joints that crack off.
  • Black powderCorrosion
    Fine black dust of iron sulfides and oxides that forms inside gas pipelines and fouls filters, meters and valves. Shop talk
  • Black startElectrotechnology
    Restarting a power system from total shutdown using generators that can start without any outside supply.
  • BlacktopAsphalt
    Everyday name for asphalt pavement, used by driveway crews, homeowners and road crews alike. Shop talk
  • BlankVacuum
    Solid flange with no hole, used to seal an unused port or to test a pump on its own.
  • BlanketRefractories
    Flexible, needled mat of ceramic or biosoluble fiber sold in rolls by density and thickness.
  • BlastPowder Coating
    To strip and roughen a part with abrasive media before coating, or as a noun, the blast room itself. Shop talk
  • Blast potCorrosion
    Pressurized tank that meters abrasive into the air stream for blasting, controlled from the nozzle. Shop talk
  • BleedBoilers
    To let trapped air out of a hot water radiator, baseboard or high point by opening its small vent until water appears. Shop talk
  • BleedTribology
    Separation of oil from a grease, either as a storage problem or as the intended release of oil to a bearing.
  • BleedVacuum
    To admit a small, controlled flow of gas into a vacuum system through a needle or leak valve. Shop talk
  • BleedWaterproofing
    Staining from fluids or plasticizers that migrate out of a sealant into porous stone or masonry.
  • Bleed-throughPhotonics
    Residual unwanted wavelength, such as leftover infrared pump, leaking past filters into the useful beam. Shop talk
  • Bleed waterConcrete
    Water that rises to the surface of fresh concrete as the heavier solids settle.
  • BleederValves
    A small vent or drain valve used to release pressure or fluid, especially between two block valves. Shop talk
  • BleedingAsphalt
    Free binder rising to the pavement surface, leaving shiny, sticky black patches that turn slick when wet.
  • Blind viaPCBs
    Via that starts on an outer layer and ends at an inner layer without passing through the whole board.
  • BlindingGeosynthetics
    Sealing of a geotextile surface by a thin layer of fine particles that blocks flow across it.
  • BlindsideWaterproofing
    Waterproofing installed on the shoring or soil face before the wall is poured against it.
  • BlinkElectrotechnology
    Momentary outage customers see when an upstream breaker or recloser trips and recloses on a passing fault. Shop talk
  • BlisteringConcrete
    Hollow bumps that form on a troweled slab when air or bleed water gets trapped under a sealed surface.
  • BlockRailroad
    A group of cars bound for the same destination, kept together so they can be handled as one unit.
  • BlockStatistics
    Group of experimental runs made under similar conditions, used to remove a known nuisance source such as day, batch or tool.
  • BloomPowder Coating
    A hazy, greasy film that forms on cured powder, often wiping off with a cloth.
  • Blow-offPowder Coating
    Blasts of compressed air used to clear water from pockets or dust from parts before they are coated. Shop talk
  • BlowdownBoilers
    Draining some boiler water on purpose to remove concentrated dissolved solids and settled sludge.
  • Blown fiberFiber Optics
    Fiber or microcable pushed through small ducts by high-speed compressed air instead of being pulled with a line.
  • BlowoutConcrete
    A form failure where formwork bursts open or shifts under the pressure of fresh concrete. Shop talk
  • Blowout tideTides
    An extreme low water caused by strong offshore winds pushing water out of a bay or sound. Shop talk
  • BlueAdhesives
    Shop shorthand for medium-strength threadlocker, the removable kind; red means the permanent kind. Shop talk
  • Blue chipsMachine Shop
    Steel chips that come off straw to dark blue from heat, read as a sign of how hard a cut is running. Shop talk
  • Blue flagRailroad
    A blue signal marking equipment that workers are on, under or between, which no one may couple to or move.
  • Blue light hazardLighting
    Photochemical retinal damage caused by staring at very bright sources rich in blue light, roughly 400 to 500 nm.
  • Blue smokeAsphalt
    Bluish haze rising off the mix that signals overheated binder and premature hardening. Shop talk
  • Blue-whitePaper Optics
    Trade description of a white shaded and brightened toward blue so it reads cool and very white. Shop talk
  • Blue wirePCBs
    Rework jumper wire on a board, named for the blue insulation often used, and the verb for adding one. Shop talk
  • BluingGears
    Shop word for marking compound brushed on gear teeth to read the contact pattern after running. Shop talk
  • BluingPaper Optics
    Mill talk for adding blue or violet dye to make a white sheet look whiter by masking its yellow cast. Shop talk
  • BlushAdhesives
    A waxy or greasy film on curing epoxy where amine hardener has reacted with moisture and carbon dioxide.
  • BMSBoilers
    Burner management system: the safety controls that handle purge, ignition, flame proving and trips on larger boilers.
  • Board housePCBs
    Shop name for a PCB fabricator, the company that turns design data into bare boards. Shop talk
  • Board opLighting
    The person who runs the lighting console during performances, executing cues on the stage manager's call. Shop talk
  • BoardyNonwovens
    Describes a nonwoven that feels stiff, harsh and papery, usually from over-bonding. Shop talk
  • BodgeMachine Shop
    A crude, makeshift repair or piece of work that does the job, but only just. Shop talk
  • Bodge wirePCBs
    Wire soldered onto an assembled board to fix a design error by joining points the copper failed to connect. Shop talk
  • BodyValves
    The main pressure-containing shell of a valve, carrying the flow passage and the end connections.
  • BoilPowder Coating
    To bubble gently and evenly like simmering water, the way a properly fluidized hopper of powder should look. Shop talk
  • Boiler horsepowerBoilers
    A boiler capacity unit equal to 33,475 Btu per hour, or evaporating 34.5 pounds of water per hour from and at 212 degrees F.
  • BoltFasteners
    A headed, externally threaded fastener meant to be tightened by turning a mating nut rather than its own head.
  • Bolt stretchFasteners
    The elastic elongation of a bolt under preload, measured directly as the most accurate check of tension.
  • Bolt-upFasteners
    The assembly and tightening of a gasketed flange or bolted joint as a job, done in a pattern over several passes. Shop talk
  • BOMPCBs
    Bill of materials: list of every part on an assembly with designators, values and part numbers.
  • BondCorrosion
    Wire or cable connection that ties two metal structures together electrically, often to control CP current.
  • BondElectricians
    Connection that ties metal parts together so they stay at one potential and give fault current a path home.
  • Bond areaNonwovens
    Percentage of a point-bonded fabric's surface covered by fused bond points.
  • Bond breakerWaterproofing
    A tape or material at the back of a joint that sealant will not stick to, preventing three-sided adhesion.
  • Bond coatThermal Spray
    The first layer sprayed on a substrate to help the following coat stick and sometimes protect the metal.
  • Bond lineThermal Spray
    The interface between a sprayed coating and the substrate, or between two coating layers.
  • Bond strengthThermal Spray
    How hard you must pull to tear a coating off its substrate, measured by gluing and tensile testing.
  • Bonded metallicPowder Coating
    Metallic powder in which the flake is fused onto the base particles so it sprays and recycles evenly.
  • BondlineAdhesives
    The layer of adhesive between two bonded parts, and in shop talk the thickness of that layer.
  • Bone pilePCBs
    Stack of failed or rejected boards waiting for diagnosis and repair, or for scrapping. Shop talk
  • BonnetValves
    The cover that closes the top of a valve body and carries the stem, packing and often the yoke.
  • Boom pumpConcrete
    A truck-mounted concrete pump with a folding hydraulic boom that places concrete right where it is needed.
  • BoomerElectricians
    Traveling electrician or lineman who follows big projects from city to city wherever the work is. Shop talk
  • BoomerRailroad
    A railroader who drifts from railroad to railroad, hiring on wherever the work is good. Shop talk
  • Boost and diffuseHeat Treating
    Carburizing schedule that first floods the surface with carbon, then lowers the potential so it spreads inward.
  • BootGeosynthetics
    Field-built geomembrane sleeve that seals a liner around a pipe or other penetration. Shop talk
  • BootWaterproofing
    A preformed or field-built collar that seals a pipe, rod or conduit where it passes through a membrane. Shop talk
  • BoothThermal Spray
    The soundproofed, ventilated enclosure where the gun, robot and part sit during spraying. Shop talk
  • BoreTides
    A wave or wall of water that runs up a river at the start of the flood tide in some funnel-shaped estuaries.
  • Bosun's chairWaterproofing
    A single-person seat suspended from roof rigging, used by caulkers and restoration workers on facades. Shop talk
  • BottleWelding
    Shop word for a high-pressure gas cylinder of shielding gas, oxygen or fuel gas. Shop talk
  • Bottom detectionHydrography
    The method a multibeam uses to pick the instant the seabed echo arrives in each beam and turn it into a depth.
  • Bottom pickHydrography
    The depth chosen from an echo trace as the true seabed, either by the sounder's tracker or by an operator. Shop talk
  • Bouncing glassBoilers
    A gauge glass water level jumping up and down instead of holding steady, a warning sign of surging or dirty water. Shop talk
  • Boundary lubricationTribology
    Regime where surfaces touch through the oil and protection comes from chemical surface films, not fluid pressure.
  • Bow and twistPCBs
    Warpage of a board, measured as deviation from flat, which upsets assembly and stresses solder joints.
  • BowlNuclear
    The steam generator channel head, the hemispherical space under the tubesheet where reactor coolant enters and leaves. Shop talk
  • BowlRailroad
    The set of classification tracks at the bottom of a hump yard where sorted cars collect. Shop talk
  • BoxGears
    Shop shorthand for a gearbox, reducer or transmission, as in the box is whining or pull the box. Shop talk
  • Brake pipeRailroad
    The air line running the full length of a train that charges and controls every car's brakes.
  • BrakieRailroad
    A brakeman, the crew member who handles switches, couplings and hand brakes under the conductor. Shop talk
  • Brass capTides
    Surveyor slang for a bench mark disk, the stamped metal cap set in concrete or rock. Shop talk
  • Brass hatRailroad
    A railroad official or manager, especially one who comes out from the office to check on crews. Shop talk
  • Braze weldingWelding
    Laying a bronze filler in a groove or fillet like a weld bead, without relying on capillary action.
  • BrazingWelding
    Joining metals with a filler melting above 450 °C but below the base metals, drawn in by capillary action.
  • BreadboardPhotonics
    A rigid, flat plate drilled with a grid of threaded holes on which optics are mounted, smaller than a full optical table.
  • BreakAsphalt
    The point when an emulsion's water separates and the asphalt droplets fuse, turning the film from brown to black.
  • BreakConcrete
    A cylinder strength test result, or the crushing of cylinders in the lab. Shop talk
  • BreakPaper Optics
    Tear of the running paper web on the machine, which sends everything to broke until the sheet is rethreaded. Shop talk
  • Break edgesMachine Shop
    A drawing note requiring sharp corners to be slightly chamfered or rounded, usually within a small range.
  • Break looseFasteners
    To get a tight or seized fastener to start turning in the loosening direction, the hardest moment of removal. Shop talk
  • Breakaway torqueFasteners
    The torque needed to start a tightened fastener turning again, used to audit joints and rate locking features.
  • Breakdown rollerAsphalt
    The first roller behind the paver, which does most of the compaction while the mat is still hot.
  • Breaking capacityElectrotechnology
    Highest fault current a circuit breaker or fuse can interrupt safely at its rated voltage.
  • BreakoutPCBs
    Drilled hole wandering past the edge of its pad, or the routing that escapes signals from a dense part.
  • BreakoutRefractories
    Escape of molten metal or slag through a failed lining and shell, the most dangerous refractory failure. Shop talk
  • BreechingBoilers
    The duct that carries flue gas from a boiler's outlet to the chimney or stack.
  • BrickieRefractories
    Shop name for a refractory bricklayer, especially in Britain, Australia and steel plant crews. Shop talk
  • Bridge jointWaterproofing
    A band of sealant laid over the face of a joint, bonding to the surfaces on either side instead of filling the gap.
  • BridgeportMachine Shop
    Shop name for any vertical turret knee mill, after the brand that made the design standard. Shop talk
  • BridgingPCBs
    Solder defect in which solder joins two pads or leads that should be separate, creating a short.
  • BridgingThermal Spray
    Coating that forms a continuous skin across the edge of a mask, so it tears or lifts when the mask comes off. Shop talk
  • BrightHeat Treating
    Describes parts that come out of the furnace clean and unoxidized, with no scale or discoloration. Shop talk
  • BrightnessPaper Optics
    The blue-light reflectance of pulp or paper, read at an effective wavelength of 457 nm and reported as a percentage.
  • Brightness padPaper Optics
    Thick, flat test disc formed from pulp slurry so brightness can be read on an opaque surface.
  • Brightness reversionPaper Optics
    Loss of brightness as pulp or paper yellows with age, heat or light exposure.
  • Bring-upPCBs
    Methodical first power-up and debugging of a new board, section by section, until everything works. Shop talk
  • BrokePaper Optics
    Paper made on the machine that will not be sold as is, and is repulped and fed back into the stock. Shop talk
  • Broom finishConcrete
    A textured surface made by dragging a broom across fresh concrete, giving slip resistance outdoors.
  • BrownoutElectrotechnology
    Sustained drop in supply voltage, caused by overload or applied on purpose to cut demand during a shortage. Shop talk
  • Bubble itHVAC
    To leak-check a joint or fitting by brushing on soap solution and watching for bubbles. Shop talk
  • Bubble-tightValves
    Shut off with no visible seat leakage when tested with air or gas under water. Shop talk
  • Bubblegum and baling wireMachine Shop
    Describes a repair or machine held together by improvised, makeshift fixes that should not still be working. Shop talk
  • BubblerTides
    Field name for a gas-purge pressure gauge that measures water level by pushing gas through an underwater orifice. Shop talk
  • Buchholz relayElectrotechnology
    Gas and oil-surge relay in the pipe between a transformer tank and its conservator that detects internal faults.
  • BufferFiber Optics
    The protective plastic layer or tube around coated fiber, either a tight 900 µm jacket or a loose gel-filled tube.
  • BugElectricians
    Split-bolt connector used to splice or tap heavy conductors, then wrapped in tape. Shop talk
  • Bug bottleCorrosion
    Field nickname for the serial dilution culture vials used to count bacteria in water samples. Shop talk
  • BUG ratingLighting
    An outdoor luminaire rating for backlight, uplight and glare, each scored 0 to 5, used in light pollution ordinances.
  • BuggyConcrete
    A small motorized or push cart that carries concrete from the truck to spots the chute and pump cannot reach. Shop talk
  • BugholesConcrete
    Small surface pits on vertical formed concrete left by air bubbles trapped against the form face. Shop talk
  • BugholesWaterproofing
    Small surface voids in formed concrete left by trapped air bubbles against the formwork. Shop talk
  • BugsCorrosion
    Field slang for the bacteria behind microbiologically influenced corrosion and system souring. Shop talk
  • Building envelopeHVAC
    The walls, roof, floor, windows and doors that keep conditioned indoor space apart from the outdoors.
  • Building pressurizationHVAC
    Controlling the air pressure inside a building relative to outdoors, usually by bringing in more outdoor air than is exhausted.
  • Built-up edgeMachine Shop
    Work material welded onto the cutting edge, which changes the tool's shape and tears the surface finish.
  • BulkPaper Optics
    Volume per unit mass of paper, the inverse of density, usually given in cubic centimeters per gram.
  • Bulk densityRefractories
    Mass of a refractory divided by its total volume including pores, a quick check on quality and compaction.
  • Bulk gunWaterproofing
    A barrel caulking gun filled straight from a pail or sausage rather than from a cartridge. Shop talk
  • BullRailroad
    A railroad police officer, the special agent who patrols yards and trains for trespassers and thieves. Shop talk
  • Bull floatConcrete
    A wide flat float on a long handle, pushed across a fresh slab right after screeding to smooth and close it.
  • Bull gearGears
    Shop name for the biggest gear in a drive train, usually the slow, heavy output gear. Shop talk
  • Bull plugValves
    A solid or tapped round-nosed male plug used to close the end of a swage, fitting or valve outlet.
  • Bull's-eyeTribology
    Round oil-level sight glass on a gearbox or bearing housing, with a center dot or line marking correct level. Shop talk
  • BullseyeStatistics
    Wafer map pattern of concentric rings or a center spot, the signature of a radial process nonuniformity. Shop talk
  • BumblefudgeMachine Shop
    Clean slang for the remote middle of nowhere, where a shop is too far from suppliers for an easy fix. Shop talk
  • BumpAsphalt
    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 in. Shop talk
  • BumpBoilers
    To energize a motor, pump or burner for a second or two to check rotation or operation. Shop talk
  • BumpElectrotechnology
    To energise a motor for a split second to check its direction of rotation before running it properly. Shop talk
  • BumpLighting
    To flash a channel or group to full instantly, usually with a console button, to identify it or for effect. Shop talk
  • BumpMachine Shop
    To make a small adjustment to an offset or position, usually a thou or less, to bring a size in. Shop talk
  • BumpRailroad
    To use seniority to take a job held by someone junior, who is then displaced. Shop talk
  • BurdenElectrotechnology
    Load connected to the secondary of an instrument transformer, stated in VA or ohms.
  • Buried viaPCBs
    Via that connects only inner layers and is completely hidden inside the finished board.
  • BurnAsphalt
    Lab shorthand for an ignition oven test, or the binder content result that comes out of it. Shop talk
  • BurnConcrete
    To steel-trowel a slab again and again at high blade pitch until it turns hard, dark and glossy. Shop talk
  • BurnFiber Optics
    Splicer slang for making fusion splices, from the electric arc that welds the glass. Shop talk
  • Burn-inStatistics
    Operating products under raised stress before shipment so weak units fail in the factory instead of in the field.
  • Burn-inWelding
    Shop word for how deeply a bead melts into the base metal or sidewalls, especially at the root and toes. Shop talk
  • Burn-off ovenPowder Coating
    A high-temperature oven that burns cured powder off racks, hooks and rejected parts.
  • Burn paperPhotonics
    Paper that marks or darkens where a laser pulse hits it, giving a quick record of beam position and shape. Shop talk
  • Burn-throughGeosynthetics
    Hole or severe thinning in a geomembrane where a welder ran too hot or stopped on the sheet. Shop talk
  • Burn-throughWelding
    A hole melted through the root of a weld where the molten metal fell out.
  • Burned outNuclear
    Having used up one's allowed dose for the period, so a worker cannot do more radiological work. Shop talk
  • BurnerBoilers
    The assembly that mixes fuel with air and holds a stable flame to heat the boiler.
  • BurnerWelding
    Shop name for the tradesperson who does torch cutting, or for the cutting torch itself. Shop talk
  • BurnoutHVAC
    A compressor motor failure that overheats the windings and contaminates the system with acid, sludge and carbon. Shop talk
  • Burnout fibersRefractories
    Plastic fibers mixed into castables that melt during dry-out, leaving channels for steam to escape.
  • BurpVacuum
    Brief, sudden pressure burst in a vacuum system from trapped gas, a warming trap or a moving part. Shop talk
  • BurritoGeosynthetics
    Site slang for a trench drain of stone completely wrapped in geotextile, often around a perforated pipe. Shop talk
  • BusElectrotechnology
    Rigid conductor or common node in a substation or switchboard where several circuits connect and share power.
  • BustHydrography
    A vertical or horizontal mismatch between overlapping lines or surveys that exposes an error somewhere. Shop talk
  • BustWelding
    Shop slang for failing a weld test or inspection, as in busting a bend or an X-ray. Shop talk
  • Butt jointAdhesives
    A joint where two parts are bonded end to end, with only the small end area carrying the load.
  • Butt rollNonwovens
    Leftover partial roll from the end of a mother roll or slitting set that is too short for a full order. Shop talk
  • Butt weldValves
    An end connection where a beveled valve or fitting end is welded straight to beveled pipe with full penetration.
  • ButterRefractories
    To spread mortar onto the faces of a brick before setting it in place. Shop talk
  • Butterfly valveValves
    A quarter-turn valve with a disc on a shaft that rotates in the bore to open, close or throttle flow.
  • ButteringAdhesives
    Spreading adhesive on both mating surfaces rather than one, to ensure full wetting and coverage. Shop talk
  • Button pusherMachine Shop
    Dismissive name for a CNC operator who loads parts and presses cycle start but does not set up or program. Shop talk
  • ButylWaterproofing
    A rubber-based sealant or tape with very low vapor transmission but little movement capability.
  • Buzz boxWelding
    Nickname for a small AC transformer stick welder, the classic farm and garage machine. Shop talk
  • BXElectricians
    Trade name used for armored cable: insulated conductors inside a spiral metal jacket. Shop talk