Help Needed: 5160

[Revolverrodger]

I made a large 5160 knife for my brother but the blade warped during quenching. I tried to re-align it cold but with zero success.
What temperature should I bring it up to so I can bend it back to shape in a vise? How high do I need to go ?
Thanks

 

[Matt River]

Heat treat after quench? 5160 is spring steel, even after temper may still be hard to deform. Look into sacrificial straightening sticks and slotted sticks for percussive and lever arm bending, try first. My own personal method if nothing else works is to put potatoes on the edge to retain hardness and use a small propane torch to soften the spine making it malleable instead of spring by oxidation colors. Cold forging over a stump or other endgrain would be another option either before with or without differential tempering. Good luck

 

[P.Brewster]

What temperature should I bring it up to so I can bend it back to shape in a vise? How high do I need to go ?

You should do all straightening at or near tempering temperature. If you have an oven, you straighten by clamping the blade in a counter-bent configuration and placing the whole setup in the oven. This is often done with a piece of angle iron, a small c-clamp, and shims such as coins. Do a search in this sub-forum, the topic has been discussed extensively.