Should be ? I remember a large bearing race that had cracks but no color What happened was that the rough grind was terrible and caused the cracking. Final grind was done by a different guy who did proper work who removed color, surface problems leaving only cracks . So I the detective checked it and found the problem on a large 3' dia custom made thrust bearing ! The problem is that in grinding too vigorously the damage happens quickly and higher than you expect .What happens on the edge and especially the tip takes only a very short time . The German metallurgist/knife maker Roman Landes has studied this carefully and found it's very easy to temper back the tip and edge of a knife . People are very surprised how easy. Therefor slow down, take your time , wet grind even by hand if you can , especially the last part of the sharpening !!