Makerx

Ya well i tried the motor oil and the knife did not harden. So i used a real light oil i found at work and it worked. Weird thing is i decided to just fully harden the blade so i just fully quenched it. Well long story short my crappy forge if thats what u want to call it (made from a turkey deep fryer n some firebrick) did not make the whole blade uniform in heat. The edge was hotter than the spine. The whole thing was non magnetic but the spine did not harden like the edge did. So by dumb luck it came out differencial treated. I did do one at work in the oven and it hardened fully but my ones at home have all been differencial treated.

I had some crack on the spine also. Most on the edge.

I used motor oil today and had good luck. I will have to test it tomorrow at work for rc hardness but it seems real hard so I put it into the oven at 350 for 2 hours to draw it back it a little. But it looks good no breaks that I can tell and I did not hear the big snap I was before lol. I did fully harden this blade. Thanks for helping!!

Thanks for the help. I was just trying to not harden the whole blade so it would have some bend to it. Maybe I will hardnen the whole blade then try to draw the spine back with a torch. What do you think?

I am using 8670 and trying to do differential quenching. I am trying to just hardned the edge only. I am quenching in water and when I do the blades break. I might try oil but am not sure. I dont want to break more blades. I also did one with firebrick clay and it broke also. Help

I called fs tool and they wont tell me what steel it is. They said it came from germany. I heat treated it and it went to 65 rockwell. I quenched it in water to do this.

I am a knife maker and am starting to get into blacksmithing. I got a large supply of the fs tool carbide tipped saw blades. Wondering if anyone has worked with this stuff? I know it is carbon steel. I was thinking of getting it analyzed and if no help of the steel maybe someone could help with a place to analyze this and maybe a cost estimate on this. Thanks for any help.