Warped a blade...I'm sweating it now

[Bowman]

So my third knife is heat treated and it warped in the process. Being a new maker, I was not fully prepared for dealing with a warp so I did what I could. I sandwiched it between two steel blocks during my first temper cycle. It didn't straighten out. I bought a toaster oven today and I have rigged a C-clamp with washers and a steel bar to flex the blade in the opposite direction to the warp. I put the whole assembly back into the oven at 400f for 1 1/2 hours. Removed and it is cooling. The blade is 1095.

If this does not work, what else can I try? Or should I try a different time/temp in the same arrangement? I have heard of guys straightening cold blades but that really gives me the 'willies'.

 

[BarryC]

After you quench the blade you have a short window of opportunity to straighten it. When all the color is gone from the blade in the quench you have reached around 900 degrees. At that point, assuming you missed the pearlite nose and will have a hard blade but, the blade isn't hard yet there is only a promise of getting hard. Until the blade reaches about 200 degrees you can *gently* bend it to straighten the warps. I have a set of 3 3/4" tubes that i use in a vise to help straighten a blade.

One other way that I have had success is to clamp the blade to a piece of angle iron using washers to get it just a tad past straight then temper it once for 2 hours at 400. If the warp is still there do it again and temper at 425. If that doesn't work I will anneal the blade then normalize it a few times and start the heat treat over. The reason I go just a tad past straight when clamped is when you release the clamp the blade will want to go back to the pre temper shape. It takes a little practice to get the bend past straight right.

 

[Bowman]

Thanks Barry. I did get the 'banana' warp out of the spine with the clamped temper cycle but there was also a warp in the edge that was a bit different. So I will clamp it up again to try to get that out. I'll consider myself lucky if I can get this blade straight. Either way I'm going to complete it. It's my first stub tang and it's important for me to finish it for practice. In the future I will be better prepared for straightening out of the quench.

 

[BarryC]

Nice looking blade. Why the narrow tang? I like a large tang. Make sure when you file for the guard fit you use a round file against the tang if you leave it squared off it will be a stress riser. Good luck finishing this one and post pics when you get her done.

 

[Bowman]

I'm a new guy Barry, the tang seemed like a good idea at the time. The ricasso is short because I did go back and use a round file. Live and learn. I have a pile of time into this blade (no grinder), so I hope I can salvage it.