GTAW NC II key terms

Equipment worn to minimize exposure to workplace hazards, including welding helmet, safety glasses, gloves, flame-resistant clothing, and respiratory protection.

A protective headgear with a filtered lens that shields the eyes and face from arc radiation, sparks, and spatter during welding.

A ventilation system that captures and removes welding fumes and gases from the breathing zone to prevent respiratory hazards.

A sudden, intense release of light and heat from an electric arc that can cause eye and skin burns; welding helmets with proper shade filters protect against it.

The process of supplying fresh air and removing contaminated air from a work area to maintain safe breathing conditions.

A formal authorization required before welding or cutting in areas where fire hazards exist, ensuring precautions like fire watch and removal of combustibles.

A designated person who monitors the work area for fires during and after hot work, with authority to stop work and extinguish fires.

A standard graphical representation on drawings that indicates weld type, size, length, location, and other requirements.

The horizontal line in a welding symbol to which the arrow, tail, and other elements are attached.

The side of a joint to which the arrow of a welding symbol points; welds on this side are shown above the reference line.

The side of a joint opposite the arrow; welds on this side are shown below the reference line in a welding symbol.

The part of a welding symbol that may contain specifications, process references, or other supplementary information.

A weld made in a groove between two workpieces, such as a V-groove or U-groove, often used for full penetration joints.

A weld of approximately triangular cross-section joining two surfaces at an angle, commonly used for T-joints and lap joints.

The shaping of edges, such as beveling or grooving, before welding to ensure proper penetration and weld quality.

An angled edge on a workpiece, created to allow full penetration in a groove weld.

The vertical portion of a beveled edge that helps control penetration and root profile in a groove weld.

The separation between two workpieces at the root of a joint, essential for full penetration in groove welds.

The portion of a beveled edge adjacent to the root that is not beveled, influencing penetration and weld bead shape.

A non-consumable electrode made of tungsten or tungsten alloy that conducts current to the arc in GTAW.

A system of identifying tungsten electrodes by color code and composition, such as EWTh-2 (2% thoriated) or EWLa-1.5 (lanthanated).

The electrical connection of the electrode and workpiece to the power source, such as DCEN, DCEP, or AC, affecting heat balance and weld characteristics.

A polarity where the electrode is negative and the workpiece is positive, concentrating heat on the workpiece for deep penetration; commonly used for steel.

A welding current that reverses direction periodically, providing a balance between penetration and cleaning action; often used for aluminum.

An inert gas, such as argon or helium, supplied to the weld zone to protect the molten weld pool from atmospheric contamination.

The volume of shielding gas delivered per unit time, typically measured in liters per minute, critical for maintaining proper coverage.

An inert shielding gas commonly used in GTAW for its good arc stability and cleaning action, especially on aluminum.

An inert shielding gas that provides higher heat input and deeper penetration than argon, often used for thick materials or high-speed welding.

The first weld bead deposited in a groove weld, which fuses the root faces and establishes penetration.

The second weld bead in a multi-pass groove weld, deposited immediately after the root pass to refine the root and prevent defects.

A weld bead deposited to fill the groove after the root and hot pass, building up the weld thickness.

The final weld bead on the surface of a joint, providing the required weld size and finish.

The process of flooding the back side of a weld with inert gas to prevent oxidation and contamination during welding of stainless steel or reactive metals.

The reaction of a metal with oxygen at high temperatures, forming scale or discoloration that can impair weld quality.

The removal of surface oxides during AC welding of aluminum, achieved by the positive half-cycle of the alternating current.

A weld defect characterized by small cavities or holes caused by gas entrapment in the weld metal.

A weld defect where the weld metal does not fuse to the base metal or to previous passes, often due to insufficient heat or improper technique.

The depth to which the weld metal extends into the root of a joint or into the base metal.

A non-destructive examination method using the naked eye or aids like magnifiers to detect surface defects and verify weld appearance.

Techniques such as radiographic, ultrasonic, magnetic particle, and dye penetrant testing used to inspect welds without damaging them.

A written document that provides the required variables and parameters for making a production weld according to code requirements.

A record of the welding variables and test results used to qualify a welding procedure specification.

The process of testing and certifying a welder's ability to produce welds meeting specified standards.