- Joined
- Feb 23, 2022
- Messages
- 150
By tensile stress do you mean a flexural stress on the blade as in bending it from one side or another? or do you mean the more traditional definition of tensile stress where the material in question is being pulled apart from one end to the other?
I'm assuming the former since blades never get subjected to pulling forces.
I'm very surprised you had a 3v chopper crack completely in half. I personally have a 3v katana heat treated to 61.5 hrc with a 20dps flat ground edge and it's never even chipped on me even against oak much less had any sort of catastrophic failure like you're talking about, and these are long blades that generally are advised you don't use them on woods much harder than bamboo and yet I had no problem in my entire 10 years of owning it
these super steels, that is to say powder metallurgy steels, especially those in the 3V and up toughness ranges have outstanding transverse toughness as well, something typical charpy test charts don't show, and while that might not mean much for flexural strength, it does mean alot for edge strength and in many cases the stronger your edge the stronger your blade in general because many catastrophic failures like what you're talking about start with a substantial chip at the edge which then propagates through the blade and if your spine isn't thick enough just goes strait through.
So every time I hear stories like this I usually think one of two things, either A. the 3v blade was improperly heat treated and many stresses remained from bad or no tempering, or B. the blade was ground super thin or was given an unusually thin spine.
Last edited:
