MOTOR TRUCK SERVICE MANUAL
BODIES AND CABS
Gas Pocket: A weld cavity caused by entrapped gas.
Groove: The opening provided for a groove weld.
Hand Shield: A protective device, used in arc welding, for shielding the face and neck. A hand shield is equipped with a
suitable filter glass and is designed to be held by hand.
Helmet: A protective device, used in arc welding, for shielding the face and neck. A helmet is equipped with a suitable
filter glass and is designed to be worn on the head.
Inert-Gas Metal-Arc Welding: An arc welding process wherein coalescence is produced by heat-ing with an electric arc
between a metal electrode and the work. Shielding is obtained from an inert gas such as helium or argon. Pressure
may or may not be used and filler metal may or may not be used.
Joint Penetration: The minimum depth a groove weld extends from its face into a joint, exclusive of reinforcement.
Lap Joint: A joint between two overlapping members.
Manual Welding: Welding wherein the entire welding operation is performed and controlled by hand.
Metal Electrode: A filler- or non-filler-metal electrode, used in arc welding, consisting of a metal wire, with or without a
covering or coating.
Nugget: The weld metal joining the parts in spot seam or projection welds.
Pass: A single longitudinal progression of a welding operation along a joint or weld deposit.
The result of a pass is a weld bead.
Planishing: Make smooth, to toughen and polish by hammering lightly.
Plug Weld: A circular weld made by either arc or gas welding through one member of a lap or tee joint joining that member
to the other. The weld may or may not be made through a hole in the first member. If a hole is used, the walls may or
may not be parallel and the hole may be partially or completely filled with weld metal. (A fillet-welded hole or a spot
weld should not be construed as conforming to this definition.)
Regulator: A device for controlling the delivery of gas at some substantially constant pressure regardless of variation in the
higher pressure at the source.
Root Crack: A crack in the weld or base metal occurring at the root of a weld.
Spatter: In arc and gas welding, the metal particles expelled during welding and which do not form a part of the weld.
Tack Weld : A weld made to hold parts of a weldment in proper alignment until the final welds are made.
Tungsten Electrode: A non-filler-metal electrode, used in arc welding, consisting of a tungsten wire.
Voltage Regulator: An automatic electrical control device for maintaining a constant voltage supply to the primary of a
welding transformer.
Weld: A localized coalescence of metal wherein coalescence is produced by heating to suitable temperatures, with or
without the application of pressure, and with or without the use of filler metal.
Weld Crack: A crack in weld metal.
Weld Metal: That portion of a weld which has been melted during welding.
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