How Good (or Bad) is 440A?

No Cobalt, that was Alvin's father!... :p and he always got exactly RC65 :D
 
yep. it's all about the heat treatment, not about the steel itself. the weight of the hammer has no dirct effect.

there are a bunch of good books around about the subject (i recommend 'material sience' by schatt/worch).

00h
 
i also have a night force with the 440A and love it. i put a convex edge on mine and it is easy to retain hair popping sharpness with a mouse pad covered block of wood and 600 grit wet/dry sandpaper.
 
Kevin Wilkins said:
. . .
If anyone actually discovered someting [about heat treating] no one else knew about, it would be so valuable to industry that they could patent it, and license their invention for more than could ever be earned making knives... and still continue to use their invention making knives if they wanted. So whenever any maker talks about a secret process in heat treating, I roll my eyes and look for those clouds of smoke he must be blowing! :p
Click to expand...

Actually, if you have a "new" process that does not result in a difference in a product that can be easily detected, you have a tough choice.

Patenting means you must disclose the details of your new process to the world. The dishonest will then use the process and force you to the difficult burden of proving that you stole the process. That burden may be economically impossible to meet -- unless someone "inside" the infringer is willing to testify (and even harder if the infringer is in another country - say one that is weak on enforcing the intellectual-property rights of foreigners).

The alternative is to try to keep the process secret, and many times that is the choice taken.
 
440A is fine for most folks. My Kershaw BlackOut is 440A in a combo edge and it has done well for me and I'm a steel snob to some extent. I've found that all 440 and all AUS6 or 8A steels are not the same though. My AUS6 Sears Craftsman "Workknife" sucks for edge keeping as a plain edge but my AUS6 Para Edge from Cold Steel is a great user and keeps a good edge for a good long while.

SOG seems to be doing something different with their AUS8A compared to Cold Steel and other companies because from what I can tell the Twitch XL Graphite is better at hanging on to its edge and perhaps harder than my Ultimate Hunter that seems to be more prone to edge rolling than the SOG which is a thinner blade but both are fine for working knives.

Of course how good any steel is depends on many things. HT being probably the most important one. I think like anything you get some that are better than others even when they are basicially the same model. If you got a good one in 440A count yourself lucky and use the hell out of it. One other thing that seems to be making a difference to some is the sub zero quench but I don't know enough about that to really comment as to if it is a good thing or a myth. Seems to make sense to me on paper though and the blades I have that have been quenched seem to perform pretty well and hold a decent edge.

STR
 
STR, I've been wondering too about the sub zero quench. I only know what I've read and I'm starting to wonder how much of it is hype. When I sent my D2 blades out for HT, I had them cryro treated. Now that I do my own HT my method seems to yield a better blade that is less brittle with no cryo. In comparing the outsourced blades to my own, I can see a difference. Of course cryo treating is a subject for debate as has been done here already.:D I'm sure it benefits some steels but as I said I know not enough about it to debate it. I only know my own comparision.
Scott
 
Without cryo, assuming you temper low, you have a lot of retained austenite in D2 which raises the toughness, however this doesn't mean cryo=brittle, you just have to adjust the tempering, cryo isn't a simple add on. Consider the performance of the Busse Combat D2 blades under heavy shock, which are cryo treated.

-Cliff
 
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