Steel toughness is measured with the Charpy V-notch test and IIRC the test results are given in ft-pounds.JD Spydo wrote: ↑Fri Apr 27, 2018 10:18 amNot sure how they measure the toughness factors in steel. But I can say by using and by experience that the old Crucible 440V is what I would personally call "tough". It is not only a great steel for Spyderedges but it's also a monster to sharpen. Of all the Spyders I've had with 440V I've never once had any chipping problems or cracks at all.
It's an interesting topic because I've noticed the blade steels that seem to be great for Spyderedges have more of a toughness factor than being super on the Rockwell scale. There are dozens of examples. Again I don't know how metallurgists measure toughness.
In knife terms the overall toughness is a function of the steel, the heat treat and even to some extent the shape. This makes it very difficult to predict toughness of a knife. Of course the material itself could be tested but it still depends on heat treat.
Another IIRC- I read a test of an outdoor knife from a mundane 440 alloy and it turned out to be very tough. I'm guessing that some of the 440 variations can be tough, especially if kept to a lower hardness level.
I've also read that Elmax is one of the tougher of the more modern steels.