Rolled in foreign material - 1.7709
By the process of rolling, material of another material was brought in into the surface of the rod wire. This defect is very rare and can be aroused by breaking out from parts of the roll fittings, like roles and blades. One of these pieces has been taken on the rolled piece and has pressed himself in into the surface, because the defect wasn't immediately noticed. Steel with 12 % chromium and 2 % carbon (tool steel) was stated at an analysis of the foreign material.
Rod wire 11,50 mm round - untreated