reading the etch..........

R

richard rosvall

Joined
Apr 24, 2000
Messages
1,693
I don't know what I did wrong, if I should just re-heat-treat it, or see how it performs. My first try at packing the spine with furnace cement, and hardening in the propane forge thing I made. Color was very uniform, non-magnetic all along, quenched in 140 degree oil. When I etched the blade, the line takes a dip towards the edge about an inch back from the tip, runs along the edge for an inch, then goes back up to where the cement was. Blade is narrow- 1/2" wide at the widest part, 5160 steel. Any thoughts? Thanks.
ssk1.jpg
 
Richard,

I can't say for sure, but it acts like the spine worked as a heat sink and drew the critical heat away from the thinner tip portion before it hit the quenchant. With clay or cement along the spine you can't heat the thickest parts up to just below critical heat unless you use a slow heating process, then you can bring the whole blade up close to critical, taking the cutting edge to critical, and not causing the spine to act as a heat sink or to harden. I hope this makes sense and it is just my opinion on what might have went wrong.;)

Bill
 
That sure is an ugly knife. I'm gonna have competition this year!:D Sorry, just kidding. You picked a Bit@h to try for a temper line. I agree with Bill. You don't have a whole lot of blade to work with width-wise and it's going to be hard to control the heat. You might want to start over again and turn that sucker over in some ATF with the edge sticking out and heat it with a torch. When the edge is hot, tip it in the fluid. Wish I had a better answer.
 
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