Help with straightening a blade - PLEASE!!!
Need your help on this one. I heat treated a large kitchen knife (CPM 154, 12" blade, 2 1/2" wide, 1/8" thick) and it took a slight bend during process. I've tried just about anything I know of and could read up about straightening bends, short of re-heat treating the knife. Let's see, I tried to:
Straighten in a vice (jig) right after coming out of the oven after the second temper cycle - snapped right back
Putting a lot of weight (close to 30 lbs) in the middle of the blade when it was still hot (only the blade ends were supported). It bent a lot, but just snapped right back
Re-heat to 425 F for 30 mins while clamped to a straight piece of angle, over-shimmed so that it bent in the opposite direction (did this three times - once just let it come to room temp by itself, once dunked the whole thing in a big bucket of water right out of the oven) - very slight reduction, but not really noticeable. Did it again, no real effect either)
After all of this, there is still probably a 1/16"bend in the blade. Should I just normalize again, and re-heat treat?
BTW, the blade was straight after normalizing and before it went into the oven the heat treat.
Thanks in advance guys!