Bearing Steel Bar (52100): Crucible Steel Alloyed with Chromium

52100 is the steel of ball bearings: about 1 % carbon and 1.5 % chromium (ASM). The standard, ASTM A295, allows 0.93–1.05 % carbon and 1.35–1.60 % chromium. Here crucible steel is melted with chromium and a little manganese, cast, forged to bar and annealed soft for working. Our method, not the factory one: factory 52100 is melted in an electric furnace and vacuum-degassed to meet the standard's limits on inclusions. A crucible melt can reach the composition, but only a lab test shows whether it is clean enough for bearings. The picture: our drawing, crucible to bar.