DEFINITIONS AND TERMS (cont) - TM-750-245-40099

TM 750-245-4

not comply with design, drawing, or specification

fusion is produced by heating with an electric arc drawn

requirements.

between a metal stud, or similar part, and the other work

part, until the surfaces to be joined are properly heated.

SOFT SOLDER: A composition of lead and tin (60-40)

They are brought together under pressure.

that will melt within a heat range of 361 to 380 degrees.

This solder is desirable for repair of electronic

SUBMERGED ARC WELDING: An arc welding process

equipment because upon removal of heat reverts from

in which fusion is produced by heating with an electric

liquid to solid state almost instantly. Higher ratios of

arc or arcs between a bare metal electrode or electrodes

lead to tin require more heat and remain in a plastic

and the work. The welding is shielded by a blanket or

state longer.

granular, fusible material on the work>. Pressure is not

used, filler metal is obtained from the electrode, and

SOLDER POINTS: A peak of lead on a solder

sometimes from a supplementary welding rod.

connection. These result from excessive solder being

applied during the soldering operation.

SURFACING: The deposition of filler metal on a metal

surface to obtain desired properties or dimensions.

SPACER STRIP: A metal strip or bar inserted in the root

of a joint prepared for a groove weld to serve as a

backing and to maintain the root opening during

welding.

TACK WELD: A weld made to hold parts of a weldment

in proper alignment until the final welds are made.

SPATTER: The metal particles expelled during arc and

gas welding which do not form a part of the weld.

TEE JOINT: A joint between two members located

approximately at right angles to each other in the form

SPOT WELDING: A resistance welding process in which

of a T.

fusion is produced by the heat obtained from the

resistance to the flow of electric current through the

TEMPER TIME: In resistance welding, that part of the

work parts held together under pressure by electrodes.

postweld interval during which a current suitable for

The size and shape of the individually formed welds are

tempering or heat treatment flows. The current can be

limited by the size and contour of the electrodes.

single or multiple impulse, with varying heat and cool

intervals.

STAGGERED INTERMITTENT FILLET WELD: Two

lines of intermittent welding on a joint, such as a tee

THERMAL SHUNT: Any metallic clamp device that is

joint, wherein the fillet increments in one line are

placed ahead between a component and area of

staggered with respect to those in the other line.

soldering. Prevents overheating of delicate electronic

components.

STORED ENERGY WELDING: The making of a weld

with electric energy accumulated electrostatically,

THERMIT CRUCIBLE: The vessel in which the thermit

electromagnetically, or electrochemically at a relatively

reaction takes place.

low rate and made available at the required welding

rate.

THERMIT MIXTURE: A mixture of metal oxide and

finely divided aluminum with the addition of alloying

STRAIGHT POLARITY: The arrangement of direct

metals as required.

current arc welding leads in which the work is the

positive pole and the electrode is the negative pole of

THERMIT MOLD: A mold formed around the parts to be

the welding arc.

welded to receive the molten metal.

STRESS RELIEF HEAT TREATMENT: Uniform heating

THERMIT REACTION: The chemical reaction between

of a structure or portion thereof to a sufficient

metal oxide and aluminum which produces superheated

temperature, below the critical range, to relieve the

molten metal and aluminum oxide slag.

major portion of the residual stresses, followed by

uniform cooling. (Terms normalizing, annealing, etc.,

THERMIT WELDING: A group of welding processes in

are misnomers for this application.) STRING BAND

which fusion is produced by heating with superheated

WELDING: A method of metal arc welding on pieces 3 /

liquid metal and slag resulting from a chemical reaction

4 inch thick or heavier in which the weld metal is

between a metal oxide and aluminum, with or without

deposited in layers composed of strings of beads

the application of pressure. Filler metal, when used, is

applied directly to the face of the bevel.

obtained from the liquid metal.

STUD WELDING: An arc welding process in which

THROAT DEPTH: In a resistance-welding

B-13