Engineering Glossary: T

83 definitions in plain language.

83 terms beginning with T. Use the filter to narrow the list, or the letters to jump to another part of the glossary.

83 terms
Tag #
A named memory location in a PLC that holds a value such as an input, an output or a variable. Automation, controls and robotics
Tangent #
In a right triangle, the ratio of the opposite side to the adjacent side. Math, units, quality and workshop
Taper #
A gradual change in diameter or thickness along a length. Math, units, quality and workshop
Tapping #
Cutting an internal thread in a hole with a tap. Materials, manufacturing and measurement
Task #
A unit of work that an operating system schedules to run. Programming, data and computing
Taylor series #
An infinite sum of powers that approximates a function near a point. Math, units, quality and workshop
Teach pendant #
A handheld device used to program and move a robot. Automation, controls and robotics
Telemetry #
Automatic measurement and transmission of data from remote equipment. Programming, data and computing
Temper #
The condition of a metal after strengthening treatment, shown by a letter and number such as T6 or H32. Materials, manufacturing and measurement
Temperature #
A measure of how hot something is; related to the average kinetic energy of its molecules. Fluids, heat and thermodynamics Read more: Temperature Converter
Temperature coefficient of resistance #
The fractional change of resistance per degree of temperature change. Electrical power and machines
Tempering #
Reheating a hardened steel to a lower temperature to reduce brittleness while keeping most of its hardness. Materials, manufacturing and measurement
Tensile stress area #
The effective cross-section area of a threaded bolt used to compute its load capacity. Mechanical design and mechanics Read more: Metric Thread Table (Coarse)
Tesla #
The SI unit of magnetic flux density. Electrical power and machines
Test data #
Data held back from training, used to check how well a model works on new cases. Programming, data and computing
Thermal conductivity #
A material's ability to conduct heat, in W/m·K; metals are high and insulators are low. Fluids, heat and thermodynamics Read more: Thermal Conductivity of Materials
Thermal diffusivity #
Conductivity divided by density and specific heat; it shows how fast a temperature change spreads through a material. Fluids, heat and thermodynamics
Thermal efficiency #
The work output of a heat engine divided by the heat put in. Fluids, heat and thermodynamics
Thermal expansion #
The increase in size of a material when it is heated. Fluids, heat and thermodynamics Read more: Temperature, Coatings and Fit Problems
Thermal resistance #
The opposition to heat flow of a layer or interface: thickness over conductivity times area, in K/W. Fluids, heat and thermodynamics
Thermal runaway #
A self-reinforcing rise in temperature and current that can destroy a component. Electronics
Thermal shock #
Stress and cracking caused by a sudden change of temperature. Fluids, heat and thermodynamics
Thermal stress #
Stress produced when thermal expansion or contraction is prevented. Fluids, heat and thermodynamics
Thermistor #
A resistor whose resistance changes strongly with temperature; NTC types fall as they warm. Electronics
Thermocouple #
A temperature sensor made of two different metals that produces a small voltage proportional to temperature. Automation, controls and robotics Read more: Temperature Sensors
Thermodynamics #
The science of heat, work and energy and how they are related. Fluids, heat and thermodynamics
Thermoplastic #
A plastic that softens when heated and hardens when cooled, and can be re-melted, such as ABS, nylon and PLA. Materials, manufacturing and measurement
Thermoset #
A plastic that cures into a permanent shape by a chemical reaction and cannot be re-melted, such as epoxy. Materials, manufacturing and measurement
Thevenin equivalent #
A simple circuit of one voltage source and one resistor that behaves like a complicated network at its terminals. Electronics
Thread lead #
The distance a screw advances in one turn; equal to the pitch for a single-start thread. Mechanical design and mechanics
Thread pitch #
The distance between neighboring thread crests; in inch threads, the reciprocal of the threads per inch. Mechanical design and mechanics Read more: Metric Thread Table (Coarse)
Three-phase power #
A system of three AC voltages 120 degrees apart, used for large loads because it delivers constant power and needs less copper. Electrical power and machines Read more: Three-Phase Systems
Throat (weld) #
The shortest distance from the root to the face of a fillet weld; the weld strength depends on it. Mechanical design and mechanics
Through-hole #
A component with leads that pass through holes in the board and are soldered on the other side. Electronics
Throughput #
The amount of data processed or transferred per unit of time. Programming, data and computing
Thrust bearing #
A bearing designed mainly to carry loads along the shaft axis. Mechanical design and mechanics
Time constant #
The time for the voltage of an RC circuit to change by 63 percent toward its final value: R times C. Electronics Read more: RC Time Constant and Filter Calculator
Time constant (process) #
The time for a first-order process to reach 63 percent of its final change. Automation, controls and robotics
Timer (microcontroller) #
A hardware counter that measures time or generates periodic events and PWM signals. Programming, data and computing
Timer (PLC) #
A PLC instruction that delays an action, such as an on-delay timer that turns on after a set time. Automation, controls and robotics
Time-series database #
A database designed to store and query measurements over time. Programming, data and computing
Time stamp #
The recorded date and time attached to a measurement. Programming, data and computing
Timing belt #
A toothed belt that meshes with pulley teeth for slip-free power transmission. Mechanical design and mechanics
Titanium #
A strong, light, corrosion-resistant metal used in aerospace and medical parts. Materials, manufacturing and measurement
Tolerance #
The permitted variation in a dimension: the difference between its upper and lower limits. Materials, manufacturing and measurement Read more: Fits & Tolerances
Tolerance (component) #
The permitted difference between a component's actual and marked value, as a percentage. Electronics
Tolerance stack-up #
The combined effect of the tolerances of several parts on a dimension of the assembly. Materials, manufacturing and measurement Read more: Tolerance Stack-up Analysis
Tolerance zone #
The region within which a feature must lie to meet its tolerance. Math, units, quality and workshop
Tombstoning #
A fault in which one end of a small surface-mount part lifts off its pad during reflow. Electronics
Tooling #
The special equipment, such as molds, dies and fixtures, needed to make a product. Math, units, quality and workshop
Toolpath #
The route that a cutting tool follows over a workpiece. Materials, manufacturing and measurement
Tool steel #
A hard, wear-resistant steel used for cutting tools, dies and molds. Materials, manufacturing and measurement
Tool wear #
The gradual loss of material from a cutting tool, which dulls the edge and changes the size of the part. Materials, manufacturing and measurement
Torque #
A twisting moment about an axis, such as that applied to a shaft or a bolt. Mechanical design and mechanics
Torque (rotation) #
The turning effect that produces angular acceleration, equal to moment of inertia times angular acceleration. Math, units, quality and workshop
Torr #
A unit of pressure equal to 1/760 of a standard atmosphere, about 133.3 Pa. Fluids, heat and thermodynamics
Torsion #
Twisting of a member by a torque. The shear stress is T r ÷ J. Mechanical design and mechanics
Torsion spring #
A spring that exerts a torque when twisted about its axis. Mechanical design and mechanics
Total harmonic distortion #
The ratio of the combined harmonic content to the fundamental, as a percentage. Electrical power and machines
Toughness #
The energy a material absorbs before it fractures, the area under its stress-strain curve. Mechanical design and mechanics
Trace #
A copper path on a printed circuit board that carries a signal or power. Electronics Read more: PCB Trace Width & Current Calculator
Traceability #
The ability to link a measurement through an unbroken chain of calibrations to a national standard. Materials, manufacturing and measurement
Training data #
The examples used to build a machine learning model. Programming, data and computing
Transducer #
A device that converts one form of energy into another, such as pressure into voltage. Automation, controls and robotics
Transfer function #
A mathematical description of a system as the ratio of output to input in the Laplace domain. Automation, controls and robotics Read more: Control Systems
Transformer #
A device that changes AC voltage by magnetic coupling between two windings. Electrical power and machines Read more: Transformers and Distribution
Transistor #
A semiconductor device that amplifies or switches signals. Electronics Read more: Transistors
Transition fit #
A fit that can give either a small clearance or a small interference, depending on the actual sizes. Materials, manufacturing and measurement
Transmissibility #
The ratio of the force or motion passed through a mount to the force or motion put in. Mechanical design and mechanics
Transmission line #
A pair of conductors that carries a signal as a wave, whose behavior matters when the trace is long compared with the signal wavelength. Electronics
Transmitter #
A sensor with electronics that sends a standard signal such as 4 to 20 mA over a long cable. Automation, controls and robotics
Trapezoidal profile #
A motion profile with a constant acceleration, a constant speed and a constant deceleration. Automation, controls and robotics
Tribology #
The science of friction, wear and lubrication. Math, units, quality and workshop
Trigonometry #
The mathematics of angles and the sides of triangles. Math, units, quality and workshop
Trip curve #
A graph of the time a breaker or relay takes to trip against the current. Electrical power and machines
Truss #
A structure made of straight members joined at their ends so each member carries only tension or compression. Mechanical design and mechanics Read more: Truss Solver (Method of Joints)
Tuning #
Adjusting a controller's settings to get a good response. Automation, controls and robotics
Turbine #
A machine that extracts work from a flowing fluid with a bladed rotor. Fluids, heat and thermodynamics
Turbulent flow #
Chaotic flow with eddies and mixing, found at high Reynolds numbers. Fluids, heat and thermodynamics
Turning #
Machining a round part by rotating it against a cutting tool on a lathe. Materials, manufacturing and measurement
Turns ratio #
The ratio of the turns on the primary winding of a transformer to those on the secondary; it equals the voltage ratio. Electrical power and machines
Two's complement #
The standard way computers represent negative integers in binary. Programming, data and computing
Typical value #
A representative value for a property, not a guaranteed minimum or maximum. Math, units, quality and workshop

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