A value used in engineering calculations which is an indicator of the ability of one material to slide on another. A low coefficient of friction indicates a low rate of wear between sliding surfaces.

The diameter of the circle a length of the electrode assumes when lying free on a smooth surface.

A form of surfacing in which one or more layers of weld metal are deposited (for example, a high alloy weld deposit on steel base metal which is to be welded to a dissimilar base metal). The buttering provides a suitable transition weld deposit for subsequent completion of the butt weld on the groove face of one member.

Deviation from edge straightness, usually the greatest deviation of side edge from a straight line.