Thanks to Steve we now have some definite numbers to look at:
The US Forest Service seems to have relaxed their standards for axes and pulaskis, but they still insist that "within 1 inch of the eye of the tool, the steel hardness shall not exceed 45 on the Rockwell C scale."
Council Tool internal standards call for tempered bit hardness of Rc 48-55 and we target 1-1/4 inches from the cutting edge.
From these two sets of data we can see that actually that USFS quoted min. hardness of Rc 45 is not at all far from the CT's stated edge-hardness of Rc 48 min.
This is important,in regards to the original question of Droppoint1 that has started this whole discussion.
Namely,it is that hardness can be a RELATIVE term,and something being "hardened",for whatever reason ,does NOT equal to being hardened excessively,or hardened insufficiently.
When we're discussing metallurgy,especially touching on specifics of someone's process,we simply must be at least somewhat cognisant of specific values .
Brian,thanks for posting those photos of the broken eye.
You're very much correct in that the grain-size in the fracture is obviously excessively enlarged(as a rule of thumb one must not be able to distinguish the individual grains).
However,your conclusion on the Hardness of that are being excessive may,or again,may Not,be right.
Personally,i'd say that there's a good chance you're right,however,without actually testing(specifically with a Rockwell tester or an analog method),we CAN'T say that,as grain enlargement does not just automatically equal excessive hardness.
I'm just all for being rational about the use of all these,sometimes tricky,terms.Otherwise things get wishy-washy quick,and all meaning gets lost.
And as a negative example i must use The Possum's mssg...
"
In the old days, the eye was soft because it was made of cheaper iron or mild steel. Good steel was so expensive, it was cheaper to forge weld just a little bit onto the cutting edge. Nowadays, I see no reason why the entire head shouldn't be heat treated. Think about it. The eye is orders of magnitude thicker than the sharp cutting edge, and doesn't take the impact directly. If a hardened eye can't stand up to the pounding, then that must also mean the edge would snap off with every swing".
sorry as i am to do so,and with all due respect,but it is exactly the sort of entirely conjectural,and based on no known metallurgical information statement...I could take an issue with about Every word in it...
However,ironically,it too has a grain of truth in it:
The entire head of any tool today IS heat-treated.
The entire head of tool at All times WAS heat-treated.(Each time you bring Ferrous alloy to A1 you're in effect heat-treating it).
The idea is to HT a tool CORRECTLY.That "correctness" is relative to the Purpose that tool is intended for.
(as usual,sorry to be a nitpicking nag...
....it's just how i myself think about it,because i often must HT tools,And figure out how and why and wherefore et c.)
