Electropolishing is primarily used to obtain a bright, clean appealing surface. However it also passivates the surface while removing burrs, sharp edges, microscopic nicks and scratches from the surface. It can smooth threads and remove heat discoloration from spot or TIG welds. Suncor products are electropolished to ASTM Standard A967.
Stretching a fitting to the point that it breaks. The percent of elongation at rupture (same as measure of ductility) is determined by dividing to total length after stretching to the original length. Elongation decreases as strength and hardness increase.