Cold-drawn round stainless-steel bars have good diameter tolerance and straightness which brings advantages for machining in CNC machines, especially bar-feed machines. Cold drawing is carried out after the hot-rolled bar has been annealed and pickled but even then, small shallow surface defects can remain. Hence, for parts or structures subjected to high loads, the cold-drawn surface should not be left unworked. The diameter tolerance of stainless-steel drawn bars is usually h9 as stipulated in ISO 286 - 2 and which is a zero-minus tolerance. In other words, the actual diameter is marginally less than the nominal one.