So I am making some kukris. Always wanted to make some, but it took me forever to draw up a design that didn't look like crap. I am doing five of these and this is the first one, my prototype so to speak:
I just did the rough grinding and some draw filing, but it needs some more refinement. Haven't even drilled the holes for the handle construction yet.
Here is where I need help: this thing kept warping on me like crazy when I was grinding it (steel is 5,5mm thick 80Crv2 btw). I cooled it regularly while grinding and I worked both sides somewhat equally.
I never had that problem before doing a stock removal blade, especially with this steel and I am not sure what causes this, but this thing is fighting me tooth and nail to keep beeing warped.
Now my first question is: how do you deal with straightening when dealing with such a large blade? (its about 40cm/15,7 inches long overall and the blade is about 28cm/11inches long) I tried straightening it by placing it on two wooden shims with the curve of the bend facing upwards so to speak and hitting it with a hard rubber mallet. That however seemed to make it worse, so I straightened in my vise, by clamping it in and just bending it straight...which worked ok, but was a major pain in the butt to do.
My second question is: do you think, given that this is just a stock removal blade, that it would benefit from a stress relief cycle before hardening? Considering the length of the piece and the problems I've had with it.
Also let me know what you think about the knife itself.
I just did the rough grinding and some draw filing, but it needs some more refinement. Haven't even drilled the holes for the handle construction yet.
Here is where I need help: this thing kept warping on me like crazy when I was grinding it (steel is 5,5mm thick 80Crv2 btw). I cooled it regularly while grinding and I worked both sides somewhat equally.
I never had that problem before doing a stock removal blade, especially with this steel and I am not sure what causes this, but this thing is fighting me tooth and nail to keep beeing warped.
Now my first question is: how do you deal with straightening when dealing with such a large blade? (its about 40cm/15,7 inches long overall and the blade is about 28cm/11inches long) I tried straightening it by placing it on two wooden shims with the curve of the bend facing upwards so to speak and hitting it with a hard rubber mallet. That however seemed to make it worse, so I straightened in my vise, by clamping it in and just bending it straight...which worked ok, but was a major pain in the butt to do.
My second question is: do you think, given that this is just a stock removal blade, that it would benefit from a stress relief cycle before hardening? Considering the length of the piece and the problems I've had with it.
Also let me know what you think about the knife itself.
but i know you guys like those super modern steels. an abs mastersmith once told me all blades, even stock removal should be normalized/stress relieved, since most steels are forged at the factory and might contain stresses. but i have also heard that is not true from other people. how about a test- next time you make one, stress relieve and whatever the rectangular bar " before" you do any stock removal to see if that might affect the warping during grinding. i have had the same problem, making the warp worse trying to straighten it. i think shimming it so its off the table did more harm than good, that gives you the ability to counterbend it too far in the other direction too easily. i had better luck with the blade laying right on the wooden bench,which would flex ( its 3/4" plywood) and hit it with a dead blow plastic hammer.
