Stainless steel is not a good material for this. Hard to machine and teeth are not that sharp.
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I use spiraled machine tap less likely to break; hob of soft steel that I caseharden to get teeth that bite like a shark.
Edited 1 time(s). Last edit at 12/27/2019 07:50PM by MKSA.
"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)