Terms starting with T

A peel test where two flexible strips bonded face to face are pulled apart in a T shape.

Test that compares a mean against a target, or two means against each other, using the t distribution.

Through-air bonded: shop and spec shorthand for fabrics bonded by hot air drawn through the web. Shop talk

Routing out each board in a panel but leaving small tabs that hold it in place until it is broken out.

The stickiness of an adhesive surface: how quickly it grabs another surface with light pressure and short contact.

To spot-weld overlapped geomembrane with a hot-air tool so it stays aligned before the final extrusion weld. Shop talk

To solder one or two pins of a part first to hold it in place before soldering the rest. Shop talk

A thin spray of asphalt between layers that bonds the new lift to the surface underneath.

A short weld placed during fit-up to hold parts in line until the full-length welds go in.

A resin added to rubber or acrylic adhesives to raise their tack and peel.

Polymer additive that makes a lubricant sticky and stringy so it clings to chains, open gears and slides.

To hang a danger tag on an isolation point so nobody operates it while people work downstream. Shop talk

Narrow strip cut from the edge of the sheet and threaded through the machine first after a break. Shop talk

Adjusting a stable process in reaction to common cause variation, which makes the output worse rather than better.

Total acid number: milligrams of potassium hydroxide needed to neutralize the acids in one gram of oil.

Adjustable transformer setting on a rectifier, used to raise or lower DC output in coarse and fine steps.

Blue hardened screw that cuts its own thread in a drilled hole in concrete or block, named for its brand. Shop talk

Masking tape used for blasting and spraying, or as a verb, masking a part off before coating. Shop talk

Flexible LED strip on an adhesive-backed reel, cut to length and used in coves, shelves and under cabinets. Shop talk

Opening through a furnace wall or bottom through which molten metal and slag are drained.

North American directional brightness measured with 45/0 geometry at 457 nm, widely called GE brightness.

Contrast ratio opacity: single-sheet reflectance over black divided by reflectance over an 89 percent white backing.

Test accuracy ratio, the UUT tolerance divided by the accuracy spec of the standard used to test it.

To cover a loaded haul truck with a tarp to hold in heat and keep the mix from crusting over. Shop talk

Total base number: the alkaline reserve left in an engine oil to neutralize combustion acids.

Tension control bolt: a structural bolt with a splined tip that shears off once the right tension is reached.

Total dissolved solids: the concentration of dissolved minerals and salts in boiler water, held in range by blowdown.

Light brown surface discoloration on stainless steel exposed to salt air or pollution, mostly cosmetic. Shop talk

Demolition of a worn or failed refractory lining so a new one can be installed. Shop talk

Rough, open streaks pulled into the mat surface by the screed as the paver moves forward.

A T-shaped fitting that splits or joins flow, with a straight run and a side branch.

A self-drilling screw with a drill-bit point that bores its own hole in steel and then threads it in one pass. Shop talk

Roll defect in which wound layers slide sideways so the roll end pokes out like an extended telescope.

The fundamental transverse mode of a laser: a single round spot with a Gaussian intensity profile.

Thin oxide colors, from pale straw to blue, that form on clean steel as it is heated in air.

Loss of toughness in some alloy steels held in, or slowly cooled through, roughly 375 to 575 °C.

Reheating hardened steel below its lower critical temperature to trade some hardness for toughness.

Rule of thumb that a gauge should resolve one tenth or less of the tolerance or process variation it measures. Shop talk

Laborer who supplies brick, mortar and castable to refractory masons and keeps the job moving. Shop talk

Mix that shoves and moves under the rollers instead of compacting, often within a certain temperature range.

The steel strand assembly in post-tensioned concrete that is pulled tight to precompress the member.

The maximum pulling load a fastener can take before breaking, stated as stress over its tensile stress area.

Portable tensile tester used on site to pull geomembrane seam coupons in peel and shear.

One ten-thousandth of an inch (0.0001 in, about 2.5 microns), the unit of precision grinding and fits. Shop talk

Covering a via with soldermask or film so its hole is sealed over instead of left open.

A flat metal or plastic strip fastened along the top edge of a membrane to clamp it to the wall.

Measuring and adjusting a building's air and water flows so every outlet, coil and zone gets its design amount.

A lever-type dial indicator with a swiveling stylus, used to align setups and compare surfaces.

Above-ground post or box with wires bonded to a buried structure, used to take CP readings.

Shorthand for a tetrasulfonated stilbene optical brightener, the general-purpose OBA type. Shop talk

Geomembrane with a roughened surface that raises friction against soil and other geosynthetics on slopes.

Glass transition temperature, above which a cured adhesive turns from hard and glassy to soft and rubbery.

Glass transition temperature: the point where a board's resin turns from rigid to rubbery and expands much faster.

Triglycidyl isocyanurate, the classic crosslinker that cures carboxyl polyesters into weather-resistant films.

Thermally grown oxide: the alumina layer that grows between bond coat and ceramic in hot service.

Radio call telling the engineer to stop the move right there, the last words of a switching count. Shop talk

Total harmonic distortion: the combined size of all harmonics relative to the fundamental, as a percentage.

The area one pound of powder covers at one mil if every particle lands on the part.

A ceramic coating system that insulates hot-section metal parts from combustion gas temperatures.

Bonding a web by heating it so thermoplastic fibers or binder fibers soften and fuse at their crossing points.

How readily a material conducts heat, the number used to size lining layers and predict shell temperature.

Transverse cracks across the lane caused by the pavement shrinking and snapping in very cold weather.

The lens effect a heated gain medium or optic creates as its center gets hotter than its edges.

Spoked connection between a pad and a copper plane that limits heat flow so the joint can be soldered.

Damaging stress from a sudden temperature change in boiler metal, such as cold water hitting hot iron.

Ability of a refractory to survive rapid temperature changes without cracking and spalling.

Family of coating processes that melt or soften material and propel it onto a surface to build a layer.

Coating powder that simply melts and solidifies on cooling, with no chemical cure, so it can be remelted.

Coating powder that melts, flows and then chemically crosslinks in the oven, so it cannot be remelted.

Thermoplastic high heat-resistant nylon-coated wire: the standard single conductor pulled into conduit.

Solid structure in a grease, usually a metal soap or polyurea, that holds the base oil like a sponge.

Adding dummy copper patterns to empty areas of a layer so plating and etching come out even across the panel.

A zirconium- or titanium-based conversion coating only nanometers thick, run in place of phosphate on many lines.

Deadpan warning, borrowed from TV comedy, that a shortcut or design choice will cause trouble later. Shop talk

One thousandth of an inch (0.001 in, about 25 microns), the everyday unit of machining talk in inch shops. Shop talk

A number-and-letter grade, such as 2A or 3B, that sets how much tolerance and allowance an inch thread has.

Making a thread by removing metal with a tap, die, single-point tool or thread mill.

The axial length over which external and internal threads fully overlap, which sets stripping strength.

A screw that displaces material to form its own mating thread in a plain pilot hole, without cutting chips.

A hardened GO and NO GO gauge for internal threads: the GO end must screw in, the NO GO end must not.

Forming threads by squeezing a blank between hardened dies, displacing metal instead of cutting it away.

Failure where the threads of a nut, tapped hole or bolt shear off instead of the bolt breaking.

An anaerobic adhesive applied to fastener threads to stop them loosening from vibration.

An anaerobic adhesive applied to threads that hardens between metal surfaces to stop loosening and seal.

Sealant bonded to both joint faces and the back of the joint, which locks it in place so it tears when the joint moves.

Inlet opening of a high vacuum pump, the flange where gas enters a turbo, cryo or diffusion pump. Shop talk

The thinnest section through a fillet weld, from the joint root to the face, which sets how much load it carries.

To hold a valve partly open on purpose to restrict and regulate flow or pressure.

Thermal bonding that pulls hot air through the web so binder fibers fuse without the web being crushed.

Hardening a steel part so martensite forms across the whole section, not just at the surface.

Mounting method where component leads pass through plated holes and are soldered on the far side.

Flashing that runs from the back of a masonry cavity out through the wall face to drain water outside.

How much gas flows past a point each second, counted as pressure times volume, in units such as mbar·L/s.

How far a supply air jet reaches into a room before it slows to a chosen speed, such as 50 feet per minute.

The distance from a lighting fixture to the surface or subject it lights, which sets beam size and intensity.

The quick pothole fix of shoveling patch mix into a hole and compacting it with the truck's tires. Shop talk

Total horizontal uncertainty: how far a sounding's true position could be from where it was recorded, at 95 percent confidence.

Shop joke name for any pinch point, blade or mechanism that is especially good at finding fingers. Shop talk

Field nickname for a surge generator that pulses a faulted cable so the fault can be heard and pinpointed. Shop talk

Titanium-doped sapphire, the broadband tunable laser crystal behind most femtosecond oscillators and amplifiers. Shop talk

Pen-shaped non-contact voltage detector that beeps or lights up near an energised conductor. Shop talk

The horizontal flow of water that accompanies the rise and fall of the tide.

A local zero for heights, computed by averaging one stage of the tide, such as high or low water, across many years.

The fixed 19-year period over which water levels are averaged to compute official tidal datums.

A lettered diamond symbol on British-style charts linked to a table of tidal stream direction and rate hour by hour.

A headland, strait or bar that can only be passed comfortably at certain states of tide, fixing the timing of a passage. Shop talk

A forecast of tide heights or currents computed from harmonic constants and astronomy, with no weather included.

The volume of water that flows into a bay or estuary on the flood and out on the ebb.

The vertical difference between a high water and the neighbouring low water.

A pocket booklet of local tide predictions for the year, handed out by marinas, bait shops and chandlers. Shop talk

The adjustment that removes the height of the tide from measured depths so they refer to chart datum.

An instrument that records water level continuously at a fixed point, the basic tool of tidal measurement.

The small difference between the Moon's or Sun's pull at a point on Earth and its pull at Earth's centre.

The small shelter on a pier or wharf that houses a tide gauge's well, recorder and electronics. Shop talk

Describes an anchored vessel lying head to the tidal current rather than to the wind. Shop talk

A graduated board fixed vertically in the water and read by eye to check a gauge against datum.

The span of time when water is deep enough, or current slack enough, for a planned vessel move or job. Shop talk

Dividing a survey area into zones, each with time and height adjustments for transferring tides from a reference gauge.

One of the crosswise beams that hold the rails to gauge and spread their load into the ballast.

To secure standing cars or a locomotive by applying enough hand brakes to keep them from rolling. Shop talk

Connection that joins a new liner to an existing one, as when a landfill cell is expanded. Shop talk

How well a weld fuses into the base metal, the bead beside it, or the end of an earlier weld. Shop talk

To go off duty at the end of a trip or shift and record the final time. Shop talk

Soft steel wire used to hang fixtures and raceways above suspended ceilings and to tie pipe to rebar. Shop talk

Tooth interior fatigue fracture: a crack that starts deep inside a case-hardened tooth, not at its surface.

Shop word for a distribution with small spread, as in a tight process or a tight spec; the opposite is wide or fat. Shop talk

Indoor fiber cable in which each fiber has its own 900 µm plastic buffer, ready to terminate directly.

The three basic ways to cut external dose: spend less time near a source, stay farther away and put material in between.

Jobsite nickname for a sheet metal worker who fabricates and installs ductwork. Shop talk

Companion value to CIE whiteness that tells whether a white leans toward green or toward red.

Titanium dioxide: the most powerful white pigment for adding opacity, used where every point of opacity counts.

A slight removal of material near the tooth tip so each tooth enters mesh smoothly under load.

Polymer strip along the edge of a scroll pump's spiral that seals each gas pocket against the facing plate.

Thermoluminescent dosimeter: a passive badge whose crystals store radiation energy and release it as light when heated.

A color rendition method that rates fidelity and saturation with 99 color samples, giving Rf, Rg and a color vector graphic.

Supply earthing in which a combined neutral and earth conductor splits into separate ones at the installation.

Earthing arrangement where the source is earthed and installation metalwork connects back to it by a protective conductor.

The edge of a weld bead, where weld metal blends into the surface of the base metal.

The total amount a dimension is allowed to vary from nominal and still be a good part.

The allowed deviation from nominal that an item or instrument may show and still be accepted.

Range expected to contain a stated share of all individual values in a population, at a stated confidence.

Defect where a small two-terminal chip stands up on one end during reflow, leaving the other end unsoldered.

A unit of cooling capacity equal to 12,000 Btu per hour, the heat needed to melt a ton of ice in a day.

The controlled storeroom where a shop keeps cutters, inserts, gauges and shared tools, checked out by request.

Making several tools or chambers that run the same step produce the same results on the same material.

Pressing and shaping freshly applied sealant with a tool to force it against the joint faces and give it a neat profile.

Painters' word for the roughness on a surface that gives a coating something to grip. Shop talk

Shop word for the bite or roughness left on a blasted surface, the grip a coating needs to hold on. Shop talk

A gear tooth cracking off, most often by bending fatigue starting in the root fillet on the loaded side.

How thick a gear tooth is along the pitch circle, the dimension that is thinned to create backlash.

The outer, functional layer of a multilayer coating, sprayed over the bond coat.

Describes a beam with flat, uniform intensity across its width and steep edges, instead of a Gaussian peak. Shop talk

High water, or the short period around it, as dock workers and boaters say it. Shop talk

To add refrigerant to a system that is low on charge without finding and fixing the leak. Shop talk

To add oil to bring a gearbox, sump or reservoir back up to its correct level. Shop talk

Soft, liquid-permeable nonwoven layer of a diaper or pad that touches the skin.

For a motor-operated valve to stop on its torque switch because it met more resistance than expected. Shop talk

A paint line drawn across a tightened nut, bolt and joint to show it was torqued and reveal any later movement. Shop talk

The relationship between the torque applied to a fastener and the preload it produces, dominated by friction.

Tightening by torque plus angle until the bolt just yields, giving consistent high preload; the bolt is single-use.

Pressure unit equal to 1/760 of a standard atmosphere, about 1.333 mbar, and the default in US labs and fabs.

A six-lobed star drive that transmits more torque with less cam-out than cross or hex recesses.

To set a tool's position by bringing it to a known surface and recording that point in the control. Shop talk

Voltage a person bridges between a hand on faulted metalwork and their feet or other hand during a fault.

Describing an adhesive modified with rubber or soft particles so the bond resists cracking, peel and impact.

The point on the paver frame where the screed's side arm pivots, raised or lowered to control mat thickness.

A streamlined body towed on a cable behind the vessel that carries side-scan or other sensors close to the seabed.

Threads per inch: the count of thread crests in one inch of length, used to state the pitch of inch threads.

Total propagated uncertainty: the combined estimate of how far each sounding could be from the truth, at 95 percent confidence.

The graph an OTDR produces, plotting returned power in dB against distance along the fiber.

The printed plot of a tooth's measured profile or helix from a gear checker, read against tolerance bands. Shop talk

Copper conductor path etched on a board layer, connecting pads, vias and planes.

Proof that a result ties back to the SI or another stated reference, with every calibration in between on record.

The documented sequence of calibrations linking a working instrument back to national or SI-level standards.

A written authority from the dispatcher, copied by radio, that lets a train occupy a set stretch of main track.

Conductive carbon trail that leakage arcs through dirt and moisture gradually burn across an insulating surface.

To square a mill head or spindle to the table so the spindle axis is truly perpendicular. Shop talk

Geomembrane pulled tight across a corner or the toe of a slope, leaving a gap underneath like a trampoline. Shop talk

The device that turns electrical pulses into sound in the water and converts returning echoes back into signals.

The share of sprayed powder that ends up on the part rather than in the booth.

A stable, portable standard used to carry a value from one lab or standard to another for comparison.

A layer of pressure-sensitive adhesive on a release liner with no carrier, which transfers entirely to the part.

Describes a pulse that is as short as its spectral bandwidth allows, with no leftover chirp.

Intermediate flow regime between viscous and molecular, where wall and intermolecular collisions both matter.

The tiny difference between where the output gear actually is and where a perfect gear pair would put it.

In-plane flow capacity of a geosynthetic drainage layer per unit width, under a given gradient and normal load.

Test of the force needed to keep a tear running across a geotextile from a pre-cut slit.

Floor word for dirt, lint, fibers and debris cured into the finish as bumps. Shop talk

The tilt of the electrode or gun along the direction of travel, described as push or drag.

One of the two conductors run between three-way switches, carrying power on whichever path is selected.

The paperwork that rides with a lot through the shop, recording each operation, furnace, time and result. Shop talk

A vertical pipe that places concrete underwater or deep in a shaft without letting it free-fall or wash out.

The short, fixed time window during which the burner control must see a pilot or main flame before it locks out.

Short test seam made on scrap geomembrane before production welding to prove the machine settings and the operator.

A distribution peaked at the center and falling linearly to zero at the limits, with a divisor of root six.

Geogrid with triangular apertures that gives fairly even stiffness in every direction across its plane.

A powder gun that charges particles by rubbing them against a plastic tube, with no high-voltage electrode.

The science of friction, wear and lubrication at every contact where parts slide or roll.

The replaceable internal parts of a valve that touch the process fluid, such as seat, disc or plug, stem and cage.

Final stage of electrical work after walls are finished: installing devices, plates, fixtures and breakers.

To open a circuit breaker automatically through its protection, or to order a breaker open by command.

A metal-seated butterfly valve whose geometry lets the seal touch the seat only at the end of closure, for tight, rub-free shutoff.

The lay-in luminaire of grid ceilings, sized to take the place of a ceiling tile, such as a 2x4 or 2x2.

Back-and-forth trace meander added to lengthen a signal so its timing matches the others in its group. Shop talk

A tide occurring when the Moon is near its greatest declination, giving the largest daily inequality.

Describes a meter or reading that computes the real RMS of any waveform, not one scaled from a sine-wave average.

The idealized exact value of a measurand, which no real measurement can reveal with certainty.

Where a method's long-run average result lands relative to a reference value; small bias means good trueness.

A ball valve whose ball is anchored top and bottom on trunnions while spring-loaded seats press against it.

Small valves at set heights on a water column, opened by hand to check whether water or steam sits at each level.

Thermally sprayed aluminum: arc- or flame-sprayed aluminum that protects steel from corrosion.

Titanium sublimation pump: a heated titanium filament that coats nearby walls with a fresh gettering film.

Tensile strength ratio: a moisture-damage test comparing the strength of soaked mix specimens to dry ones.

Earthing arrangement where the supply and the installation each have their own separate earth electrode.

Time-temperature-transformation chart showing how long austenite takes to transform when held at a fixed temperature.

Empty panel enclosure, the steel back box that goes in at rough-in before the interior and cover arrive. Shop talk

The thick flat plate at each end of a firetube boiler shell that the tube ends are rolled or welded into.

Growth of knob-like mounds of rust and deposits on the inside of iron and steel water pipes.

Common trade name for repointing brick, though strictly it is a decorative technique with a contrasting thin joint line. Shop talk

Portable powered cable puller that winds rope on a capstan to pull wire through long or heavy conduit runs. Shop talk

LED lighting whose color temperature can be adjusted, typically between warm and cool whites, by mixing LED channels.

Test uncertainty ratio, the tolerance being checked divided by the expanded uncertainty of the measurement process.

Highly refined, lightly additized circulating oil built to last for years in steam, gas and hydro turbines.

High vacuum pump whose rotor blades spin at tens of thousands of rpm and bat molecules toward the exhaust.

A pretensioning method that snugs the nut, match-marks it, then turns it a fixed fraction of a turn.

The moment the tide changes from rising to falling or the current from flood to ebb, or the reverse. Shop talk

Transfer of the running sheet from a full reel spool onto a new empty one at the paper machine reel. Shop talk

The ratio of a burner's highest to lowest firing rate, such as 4 to 1 or 10 to 1.

Temperature uniformity survey: a test mapping how evenly a furnace holds temperature across its work zone.

Total vertical uncertainty: the depth part of a sounding's uncertainty, judged against a depth-dependent limit.

Track warrant control: running trains outside CTC on dispatcher-issued warrants with fixed limits.

Shop slang for making a small adjustment to an instrument to bring its readings back toward nominal. Shop talk

Process that melts two electrically charged wires in an arc and blows the molten metal onto the part with air.

Describes a bolt or screw that snapped in torsion while being tightened or removed, leaving the stub behind. Shop talk

Describing a finish built from a base coat and a top coat, each sprayed separately. Shop talk

A Y-shaped cable that connects two lighting fixtures to a single circuit so they are controlled together. Shop talk

Splicer slang for fiber that has only its 250 µm acrylate coating, with no tight buffer over it. Shop talk

Orienting a flange so two bolt holes straddle the top centerline instead of one hole sitting dead on top. Shop talk

Describing an adhesive supplied as a resin and a hardener that start curing only once mixed.

Cleaning a joint face with a solvent-wet cloth followed immediately by a dry cloth, before the solvent evaporates.

Difference in properties between the two faces of a paper sheet, such as color, brightness, gloss or texture.

Shop shorthand for an uncertainty quoted at k = 2, roughly 95 percent coverage. Shop talk

A joint with an outer rain seal and an inner air seal separated by a drained cavity.

Thermostatic expansion valve: a metering device that adjusts refrigerant flow to hold constant evaporator superheat.

Brand name used for plastic cable ties, the self-locking straps that bundle and secure wiring. Shop talk

Putting a number on an uncertainty component by running statistics on your own repeat readings.

Sizing an uncertainty component from existing knowledge such as certificates, specs or resolution, with no new repeat data.

The everyday portland cement, certified to meet both general-purpose Type I and moderate sulfate-resistant Type II limits.

High-early-strength portland cement, ground finer so concrete gains strength in days instead of weeks.