Too much of a good thing: choosing the right steel
Up until now, I've mainly worked with 3 types of steel: old file, O1, and 52100
I make not only razors, but also kitchen knives and general purpose stuff. And I am still experimenting with various ways of doing things. I'm interested more in learning things than selling things, and see the latter as a way to finance the former.
Anyway, I work with 52100 only to have something different from O1. Of course it is different from old file too, but given the unknowns in old file, old file is different from old file as well, and not a known reference. To be correct, I use a bit of niolox too, which is stainless knife steel. I only use it rarely, and only because it is wife-proof. I don't really like it, but a man's gotta do what a man's gotta do when he wants to make a knife for his wife.
This weekend I heat treated pieces of O1 and 52100, and only tempered them to the point before I got straw color. In other words, barely tempered at all. 180 degrees celsius is what the thermometer I'd put in the oven read. And I had to cut the tempering short at 30 minutes because my wife needed the oven to bake bread, and she is boss of the kitchen. Force majeure.
Then I let them air cool and took them to the grinder. The O1 was hard, obvisously. But I could grind it and shape it. The 52100 was a different story altogether. It mocked me. After 10 minutes of grinding, the piece was just a hair thinner than what I started with. As hard as it may be to believe, my 40 grit belt was only giving it a mirror shine. I've now re-tempered the things to straw. We'll see how that goes.
Steel is like jewelry and people sometimes want something exotic, just for the sake of being different. From a practical point of view, I think sometimes, something is just the wrong tool for the job. If you look at the requirements of a razors edge, the major requirement is high hardness and a small grain size. Toughness doesn't really come into the picture much. O1 may be less tough than 52100, but for shaving this doesn't matter. However, for working it, it does. A lot. Making a 52100 razor is much more work than making an O1 razor. And then there is honing to consider. Honing a 61 or 62 HRc 52100 blade is going to get boring, tedious, and likely to give you a tennis elbow.
I'm not sure I am trying to make a specific point here. Just sharing an observation that too much of a good thing can be a bad thing, and not choosing the right steel for the job just means you spend more time and more money to make the same thing in terms of requirements of the end product. Sometimes, less is more.