COLD FORMING OR COLD HEADING OR COLD WORKING – When fasteners are produced without heating or small heat below recrystallization temperature (So the raw material bond of stainless remains unchanged) by processing metal wire against various dies at high speed to form a fastener’s head or basic shape. Cold working causes an increase in tensile strength and hardness (known as work hardening ) and a decrease in ductility.
COPPER - A reddish metal that is an excellent conductor of heat and electricity. It is malleable, ductile and non magnetic with low to average strength and good corrosion resistance.
CREEP STRENGTH - A measure of the resistance of fasteners to stress under elevated temperatures. At higher temperatures, a fasteners can change in dimension under the same load, and is called creep. Creep can cause the loosening of fasteners as temperature increases.
DISCONTINUITIES - A variety of small or large disfigurations in a fastener such as pits, tool marks, voids, laps, folds, and seams and inclusions. Minor discontinuities are permissible in both commercial fasteners and those made to various specs.
DRAWING - Where raw material shaped like wire is pulled through a die to reduce its diameter to that needed for particular fastener being manufactured.
DUCTILITY- the ability of a fastener to deform before breaking (for example an elastic would be more ductile than a diamond). Ductility is a measurement similar to elongation.
ELONGATION - Stretching a fastener to the point that it breaks. The percentage of elongation at rupture (same as measure of ductility) is determined by dividing the total length after stretching to the original length. Elongation decreases as strength and
hardness increases.
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