
Originally Posted by
Mike Blue
To my eye, you may have run into some microscopic inclusions that leave pores behind when they are dragged away from the steel by the stones. In my time grinding steel bars, there are several pieces of steel I remember, that have proven to be a poorly mixed solution with inclusions and undissolved mystery steel globs that are not homogenous from the mill. It all appeared to be fine and normal as a flat surface ground bar, until a process change showed the difference. The spec sheet said it was what I bought, but occasionally there are acceptable deviations, at least to the steel manufacturer. They can always sell you another bar of steel.
It could be microscopic porosity, but for either problem, why do these only appear along the bevel and are not seen elsewhere on the ground surfaces of the hollows? This is not a laminated blade and there should be an even distribution of such flaws, not simply limited to the very center of the bar and only showing up along the bevel. An additional strange feature is that these pores seem to miss the working edge too.
I would call them flaws, but of the non-fatal type (referencing a Japanese way of judging a blade's potential, i.e. they do not cross the edge and compromise it as a tool) and fully capable of being used normally. You will always know these pores are there. Shave, hone, shave, hone and continue observing what happens to them. If they are small they will disappear (others might appear). If they are larger edges of bigger flaws they will open up and be more visible. You still have a working razor that will tell its story over time. It's not something I'd toss in the junk box. I'd tell the maker and share this information with them. If it was an O-1 razor with my name on it, I would want to know.
I don't know that the heat treatment is the problem. This is not to say that it couldn't be. Perhaps (cautiously perhaps) not enough material was removed after heat treating, perhaps there is some decarb'd steel. My experience, for normal O-1, in my time heat treating steels, is that it is not a tricky or delicate steel and is quite predictable with few surprises, except those that no one could anticipate. I don't know enough about the heat history of the blade in the hands of the maker to be sure of any possibility in this variable.
It would be really good to know what the maker did to this bar of steel from beginning to end.