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I'm finding renewed interest is a few things I've thought about for years (decades, actually).
Cryogenetic treatment - Reports are that it makes a significant improvement in the steel. So I'm sending off a dozen of my finished blades.
I should complete testing and report back here sometime in 2024.
OK, here is something kinda crazy - It is pretty well accepted that large grain growth (from overheating the steel) is not good for tool
edge holding. Maybe orientation of the crystalline structure is also very important but never utilized because how could you align crystals
one way or the other just by hammering or heat treating.
What if blades were quenched (when red hot, when the structure is most quickly changed) in a strong magnetic
field to orient the crystals?
I’ve got a field coil from a large diesel generator, big enough to put a pot of hardening oil inside.
Don’t know the best way to wire the coil (DC, AC, voltage???) but am looking into it...
Posted 3/18/24: I've sent off a dozen SN-M blades for cryogenic treatment. They were given my regular full heat treatment first,
and will be post tempered to 300F after cryogenic to ensure against brittleness. Will be
testing them compared to my standard knives in a few weeks. Really looking forward to this!
Posted 4/2/24: Just got the SN-M blades back! Will be doing the final sharpening and hafting onto handles this week, then testing
against untreated blades. Posting the results here soon.
Posted 11/12/24: First test was inconclusive. Tried comparing a cryogenic treated blade against one of my regular blades.
Began by carving the end grain of dry red cedar to make sure both blades were fine and sharp enough to make smooth cuts without any tearouts.
Progressed with aggressively carving the end grain of dry honey locust to try and dull the blades. Then went back to the red cedar to see whether
the blades still made smooth cuts without tearing. Both blades held up well, with no discernable difference. I tried this several times with the same results.
I was actually a bit surprised my regular blades did so well. Will have to try carving something more difficult than locust to see if the
cold treatment makes any difference...
Posted 5/1/25: I send 3 of my regular Medium Straight Knives and 3 that were cryogenic treated to a customer in Oklahoma for
extensive testing. This is his concise report:
"Extensive testing was completed following multiple parameter's with 6 test tools.
It was concluded that using cold treatment repeatedly provided over two times the amount of
edge retention. Cold treatment provides further grain refinement resulting in better overall
performance of the steel. Notably edge retention and wear resistance. Sharpening requirement
differences were negligible."
Going forward, I will be having all of my straight wood carving knives cryogenically treated in the future.
My "Medium Straight Knife" will be replaced with the cryogenically treated version in a few months (at a slightly higher price).
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