I was reading up on the Council Tool Camp Carver axe and noticed that it is 5160 tempered to 55. From what I have read from Larrin's work, 5160 appears to be one of those steels like A2 where you have to "take what the chemistry gives you." Too hard or too soft, not so good. Same with going too soft on steels like CruForgeV. 55Rc would indicate that they might be tempering in the range that can produce TME. I don't think that embrittlement is quite the issue with the plain 10xx steel that they use for ohter acxes, so they can leave them as the USFS specs of that mid 50's range. The "sweet spot for 5160 according to Larrin is like 1500-1525/375-400. that gvives you like 58-59 Rc. Above or below, it looks like you see a drop off in toughness pretty quickly. Any thoughts?