Tack Hammer - A special hammer with a magnetic head for inserting small nails or tacks.

Tack Weld - A weld made to hold parts in proper alignment until the final welds are made.

Tandem Mill - Arrangement of rolling mills, in direct line, allowing the metal to pass from one set of rolls to the next for the
reduction of steel.

Tang - The flat on the shank of a cutting tool, such as a drill, reamer or end mill, that fits a slot in -the spindle of a machine to
keep the tool from slipping.

Tap Wrench - A bar with a hole and clamping device or T-bar design to hold a tap used to make internal threads.

Taper Roller Bearing - A bearing composing of a cone of rollers and a matching cup for the rollers to sit within.

Tappet - A tappet is an arm, collar or cam within a machine which imparts intermittent motion.

TDC - Top dead centre.

TDS - Total dissolved solids

Tee Joint - A joint between two members located approximately at right angles to each other in the form of a T.

Telescoping Gauge - A T-shaped gage used to measure the diameter or width of holes.

Temper Colours - The colours which appear on the surface of steel heated at low temperature in an oxidizing atmosphere.

Temperature Range - The minimum to maximum temperature over which a piece of equipment will operate.

Tensile Strength - The ultimate strength of a material prior to fracture when subjected to an increasing tension load.

Tensile Stress - Stress acting on the cross-sectional area of a body normal to the tension force acting on the body.

Theodolite - A theodolite is an instrument used in surveying for measuring horizontal and vertical angles.

Thermal Cycling - Subjecting a product to pre-determined temperature changes, between hot and cold extremes.

Thermal Resistance - The property of a material, device or system that impedes the flow of heat.

Thermal Shock - Stresses induced in a material because of a rapid temperature change or a thermal gradient.

Thermit Crucible - The vessel in which the thermit reaction takes place.

Thermit Mixture - A mixture of metal oxide and finely divided aluminum with the addition of alloying metals as required.

Thermit Mould - A mould formed around the parts to be welded to receive the molten metal.

Thermit Welding - A group of welding processes in which fusion is produced by heating with superheated liquid metal and
slag resulting from a chemical reaction between a metal oxide and aluminum, with or without the application of pressure.

Thermite Process - The method of obtaining liquid metal by reduction of the oxide with aluminium powder.

Thermocline - The depth at which an inflection point occurs in a lake temperature profile

Thermocouple - The junction of two dissimilar metals which has a voltage output proportional to the difference in
temperature between the hot junction and the lead wires (cold junction)

Thermoplastic - A polymer that softens or melts on heating, and becomes rigid again on cooling.

Thermoset - A polymer that solidifies when heated, i.e. it sets and cannot be changed; some polymers behave like this
because the heating process causes the chains of the polymer to bind to each other, via cross-links, and these cannot then
be broken

Thermowell - A closed-end tube designed to protect temperature sensors from harsh environments, high pressure, and flows.

Thin Rod - The moment of inertia of a thin rod.

Thiols - Organic compounds which contain the "-SH" functional group. Also called mercaptans

Third Class Lever - The force is applied between the load and the fulcrum.

Thou - An abbreviation of thousandths of an inch. A unit of length used by engineers.

Thousandths of an Inch - Often abbreviated as thou. A unit of length used by engineers.

Thread - A helical projection of uniform section on the internal or external surface of cylinder or cone.

Thread Angle - The angle formed by the two sides of the thread with each other.

Thread Axis - A line running lengthwise through the centre of the screw.

Thread Crest - The top surface joining the two sides of a thread.

Thread Depth - The distance between the crest and the root of a thread.

Thread Flank - The thread flanks join the thread roots to the crest.

Thread Height - This is the radial distance between the minor and major diameters of the thread.

Thread Length - The length of the portion of the fastener with threads.

Thread Micrometer - A micrometer in which the spindle is ground to a point having a conical angle of 60 degrees.

Thread Pitch - The distance from a point on one screw thread to a corresponding point on the next thread.

Thread Pitch Diameter - The diameter of a screw thread measured from the thread pitch line on one side to the thread pitch
line on the opposite side.

Thread Root - The bottom surface joining the sides of two adjacent threads.

Thread Runout - The portion at the end of a threaded shank which is not cut or rolled to full depth, but which provides a
transition between full depth threads and the fastener shank or head.

Throttle Pedal - A pedal that when pressed is connected to the engine and demands more torque.

Throughput — The amount of material being processed at a facility or processing plant

Thrust - The force exerted in any direction by a fluid jet.

Thrust Bearing - A bearing designed to only take axial or thrust load.

TIC - Total installed cost

Timber - A hard substance which forms the branches and trunks of trees and which can be used as a building material, for
making things, or as a fuel.

Tinners Hammer - A hammer used to shape tin plates.

Toe-In - Setting the front wheels to toe in will mean that when driven the wheels will tend to be aligned.

Toe-Out - Setting the front wheels of a front wheel drive car to toe out will mean that when driven the wheels will tend to be

Tommy Bar - A rod which is inserted into the holes of a box spanner.

Ton (refrigeration) - 12,000 Btu/hour

Tons per Square Inch - Old imperial unit of pressure, abbreviated as Tsi or tonf in-2.

Top Dead Center - The position of the crank when the piston is in its farthest position from the crankshaft.

Topographic - Using contour lines on a map or other image to represent the physical characteristics of an area.

Torch Brazing - Bonding is produced by heating with a gas flame and by using a nonferrous filler metal having a melting point
above 427°C.

Torque - The torque or turning moment acting on a body is defined as the product of the magnitude of the force and the
perpendicular distance of the line of action of the force from the axis about which the body is being rotated.

Torque Steer - A tendency for a car to turn in a particular direction when power is applied.

Torque to Power - Calculate power in PS given a torque in Nm at a given speed.

Total solids - The amount of organic and inorganic matter which is contained in a water

Total suspended solids - The amount of suspended (filterable) matter in a water

Trammel - A metal rod having pointed ends, used to mark off a span equal to its length.

Transducer - Electrical device that converts quantities such as mechanical rotation, electrical voltage, current or power to a
low signal value capable of being used in a SCADA monitoring system.

Transformer - Static electric device consisting of a winding or two or more coupled windings, with or without a magnetic core,
for introducing mutual coupling between electric circuits.

Transpiration - The loss of water from plants through leaves and other parts

Tribology - The technology of interacting surfaces in relative motion and concerned with the design, friction, lubrication, and
wear of contacting surfaces that move relative to one another.

True Strain - The ratio of the change in dimension, resulting from a given load, to the magnitude of the dimension
immediately prior to applying the load.

True Stress - The load applied to a material divided by the cross sectional area over which it acts.

Trunk Line - The main line from which other lines originate.

TS - Total solids

TSS - Total suspended solids

Tsi - Abbreviation of Tons per Square Inch.

Tungsten Carbide - Strong alloy often used in grinding and polishing.

Turbidity - Water clarity.

Turbine - A type of engine.

Turbocharger - A supercharger powered by an exhaust-driven turbine.

Turbulence - Describes fluid motion disturbed from its average behaviour by random fluctuations over a range of temporal
and spatial scales.

Turnkey - A project in which all components are within a single supplier's responsibility

Twin - Two portions of a crystal with a definite orientation relationship.

Twist Drill - A commonly used metal-cutting drill, usually made with two flutes running around the body.

Two-Stroke Engine - An internal-combustion engine that has one power stroke per revolution.

Tyre - The rubber part of the wheel which contacts the ground.

Tyre Bead - That portion of the tire that bears against the rim flange.

Tyre Gauge - An instrument for determining the pressure in a tube or tyre.
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