Thread: Micro holes on modern production razor?

I added some photos via phone camera and an led 30X loop please bear with me. The photo show what looks like scratches on the bevel but with a 60X loop you can see they are holes that have grabbed some grit while honing. I just re honed this razor starting at 220 all the way to 12k and the holes are still there!

O-1 material has been used by many to make some beautiful razors and knives. However some artisan makers may not understand the heat treat and quenching problems that come with using O-1. You can study this from a Crucible handbook or study it online at crucible.com. although the problems you mention are common when O-1 is improperly heat treated and not quenched properly. I am not saying this is what happened, but with over 18 years as a machinist and tool&die maker it is not the first time I have seen or heard of these problems. Hope this may help a little.

Originally Posted by Ron187524

O-1 material has been used by many to make some beautiful razors and knives. However some artisan makers may not understand the heat treat and quenching problems that come with using O-1. You can study this from a Crucible handbook or study it online at crucible.com. although the problems you mention are common when O-1 is improperly heat treated and not quenched properly. I am not saying this is what happened, but with over 18 years as a machinist and tool&die maker it is not the first time I have seen or heard of these problems. Hope this may help a little.

Thank you! What you said is what I was thinking in theory!

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.

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.

Thank you for this very clarifying post! These all came from the same bar, 1 razor is by far worse than the other 2. I have received great shaves from these razors. Just knowing there are these holes bothers me way more than than the function of the razors. The makers have already worked with me over the issue. I am glad I posted this so I can understand what is possibly going on with the steel again thank you all

Originally Posted by dshaves

I would say they are in the middle of matte and polished finish. They shave well but the edge has not met the holes yet.

I do not see any holes on your pictures, but here's what can happen:

• moisture can get trapped in them then oxidize the steel and expand them
• if they don't go through the middle of the blade by the time they reach the edge you may have honed past the hole and have a plain solid steel
• if they reach the edge you'll have to hone past them to a clean straight edge again