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Thought I could skip the annealing step on a spring steel blade... big mistake
Rushed a bowie knife project last month and figured I could just normalize the steel instead of doing a full anneal before grinding. Ended up with a blade that cracked right down the middle at 60% done. Lost about 8 hours of work. Anyone else learn this the hard way or am I the only one who thought they could cheat on heat treat prep?
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sageadams8d ago
Damn, you normalize three times? That's wild. I've been doing this for years and only do two cycles religiously. @jordan_webb you got me rethinking my whole setup now. Pretty sure I've been asking for trouble with just one normalize on my 1075 blades. Might have to try that lime bucket trick from the_simon too. Your camp knife story hit close to home, that's exactly the kind of loss that makes you want to throw your grinder through a wall.
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Did you try a few normalize cycles before the grind or just one? I had a similar mess on a 1095 camp knife about two years back, but after that I started doing a full thermal cycle soak in my forge and then a slow cool in vermiculite before any grinding. It adds maybe two hours to the process but I haven't had a crack since.
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the_simon20d ago
I live in a small town in Oregon and have been making knives for 12 years now. I normalize spring steel three times before I even think about letting it cool slow. Three cycles, each one dropping the temp a bit from non-magnetic down to about 1200 degrees. Then it goes straight into a bucket of dry lime for a slow cool overnight. The problem with only doing one normalize is you don't get the grain structure fine enough, and that's what causes the cracking. I lost a nice 1084 chef knife the same way you did about 5 years back. Now I treat every blade like it's going to crack if I rush it, because I know from experience it will.
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