Welding Glossary T

Tack weld A small weld used to temporarily hold together components of an assembly until they can be welded.
Tack welding tip A pointed tip for a plastic welding torch, used to tack weld plastic weldments.
Tail The ãVä shape, drawn at one end of a welding symbol, in which special notes are placed.
Tank A thin-walled container for liquids or gases.Tank walls are thinner than the walls of cylinders used for pressurized gases.
Tap One of several electrical contacts available on the controls of a resistance welding machine.Each tap provides a different range of amperage for the electrodes.
Tap settings The various tap positions available on the resistance welding machine.
Teach pendant An electronic control used to program a robot to perform a series of actions; the sequence of movements is placed in computer memory as a program.
Teflon liner A smooth seamless tubing used inside a cable to make electrode wire feed more smoothly to a MIG (GMAW) gun.Teflon liners are typically used for feeding aluminum wire.
Tempering A heat treating process in which metal is heated to a temperature just below its melting point.This heating decreases the metalâs hardness, while increasing its toughness.
Tensile shear The amount of force required to pull a spot weld apart in a direction perpendicular to the weld axis or ãin shearä.
Tensile strength The maximum pull stress in psi which a test specimen is capable of developing.
Tensile test A test in which a specially prepared sample is pulled until it fails.The test determines the weldâs ability to withstand forces that would pull it apart.
Terminals The physical connectors on a welding machine for attaching the workpiece lead and the electrode lead.
Thermal radiation Heat rays given off by a welding arc or by the heated base metal.
Thermal spraying A process in which a material (metallic or nonmetallic) is heated and sprayed onto a surface.
Thoria An alloying element used in TIG (GTAW) tungsten electrodes to aid in arc starting.
Three-Phase Circuit Electrical circuit which delivers three cycles within a 360 degree span of time, each cycle is 120 degrees apart.
Throat depth The distance measured from the center of the electrodes to the frame of the resistance spot welding machine while the electrodes are closed (in contact).
Throat of fillet weld The distance from the weld face to the weld root.
Thumb switch A switch mounted on a TIG (GTAW) torch to control the amperage; so-called because it is usually operated by the welderâs thumb.
TIG Welding (GTAW or Gas Tungsten Arc) Tungsten Inert Gas (TIG) Welding is a process which joins metals by heating them with a tungsten electrode, which does not become part of the completed weld.
Tip Flat Refers to the geometry of a specific ground end of a tungsten electrode for TIG (GTAW) welding.The tip flat is a small flat face on the end of the ground tungsten electrode.This geometry is recommended for certain welding applications to improve arc starting and to reduce arc wandering.
T-joint A joint formed by placing one metal against another at an angle of 90 degrees.The edge of one metal contacts the surface of the other metal.
Toe of weld The junction of the face of the weld and the base metal.
Torch A device used in the TIG process to control the placement of the electrode, transfer current and direct the flow of the shielding gas.
Torch angle The angle to the base metal or weld axis at which the torch is held while welding.
Torch body The main portion of the welding torch, to which hoses and cables are attached.
Touch Start A procedure for starting TIG welding in which the tungsten is touched to the workpiece and when the tungsten is removed, an arc is established.
Toughness The ability of material to withstand all types of stresses without tearing or breaking.
Track A straight or curved guide for an electric motor-driven carriage that carries a cutting torch.
Trail Cup


A special gas cup used in TIG (GTAW) welding of non-ferrous or oxidizing metals to provide additional shield gas coverage over the weld zone as the torch is moved along the weld line.
Trail Shield



Transferred arc An arc that is established and maintained between the electrode and the workpiece.
Transformer An electrical device used to reduce or increase voltage.
Transition current The amount of current required to convert from globular transfer to spray transfer.
Tungsten A metallic element with an extremely high melting point used in making TIG electrodes.
Tungsten Grinder A device designed to grind the proper geometry onto the end of a tungsten electrode used in TIG (GTAW) welding.Proper electrode grinding and geometry is essential in achieving optimum weld integrity.See Arc-Zone part number···.
Tungsten inclusions In TIG (GTAW) welding, a weld defect caused by getting tungsten from the electrode in the weld.
Two-stage regulator A regulator that reduces cylinder pressure in two stages (steps).