Heat treating throwing knives 13" and 13 oz, will be just steel with no handle

[skmd11]

I have made a few basic blades for throwing. The knife is 13' and 13 ounces, will be just steel.
Should I harden the complete blade or just the tip? I am thinking heat treating the complete knife may make the whole blade too brittle.

skmd11

 

[pwest]

You should probably heat treat the entire blade. See e.g. how FlyingSteel makes theirs at: http://www.flyingsteel.com/tech-info

-Phil

 

[P.Brewster]

Complete blade. When you do spot hardening, you get a transition from hard to soft. You will inevitably get a kink (bend) at that transition.

One thing you can do is fully harden the knife, then do a differential temper (with a torch) to draw down the body a bit.

So a transition from hard to soft will give you a bent knife, but a transition from hard to slightly-less-hard will be fine.