Choil-less BT4 in CPM-M4 WIP

I think that's what I'll go for in mine. Or maybe I should just branch out and pony-up for M4.
 
I think that's what I'll go for in mine. Or maybe I should just branch out and pony-up for M4.

It is hard to go wrong with good ole A2. Easy to grind and pleasure to Heat Treat. Tough, holds a good edge, and gets stupid razor sharp because of its fine grain structure. Whats not to like.

But M4 is also very tough and holds a phenomenal edge. It on the other hand requires a more rigorous heat treat regimen at higher temps and is also a real bear to grind once harden. The later probably doesn't mean much to the buyer but it is a big deal for the guy working it. It is at least 2-3 times harder to work with than A2 after heat treat.
 
Yeah, I've only ever had A2 by BRKT back when I was first getting into knives, but I remember it treating me pretty well.

Sounds like M4 would be a pain to sharpen if you let it go truly dull.... How's corrosion resistance with M4? I've been annoyed at how easily my O1 knives rust if they aren't coated with a patina.
 
M4 will rust fairly easily if not maintained properly. I would guess that it is probably similar to A2 in the corrosion resistance.
 
It shouldn't be too hard to maintain with the frosty finish. But it will rust if you look at it wrong in a bead blast type finish.
 
M4 is awesome stuff. I like it a great deal. Holds a awesome edge for a looooong time. These ones are still at 63-64 rc after the 3rd 6hr temper. Will have to do another one and bump up the temp again to bring them down to 61 or so.
 
Do you have to bring them down to 61 to keep them from being too brittle? What are the downsides to keeping them at 63 besides being a nightmare to resharpen?
 
a brittle knife will snap if you twist your knife or pry with it.
 
Do you have to bring them down to 61 to keep them from being too brittle? What are the downsides to keeping them at 63 besides being a nightmare to resharpen?

Yes the larger bt4s will be brought down to around 60-61. Yes one of them will have oj scales.
 
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