Ed, I tried to differentially heat treat my blade this AM. The blade is a tanto style, chisel ground 1/8" 1095 steel. It warped, and I'm assuming it was due to the chisel grind and only 1/8" stock. I could easily straightened it by placing the blade on a counter and using my body weight. Since I was able to straighten it with out a vise, do you think it is to soft? Should I heat treat the whole blade? The design is for defensive use, mostly thrusting movements, some slashing.

BTW, thanks for the intro to forging and heat treating. Now I need to get an anvil and some hammers. There was an anvil in the consumers press about 3 weeks ago, missed out on that one :(

One the warpage....my money is on two factors. One being the 1/8" thickness, and likely the other was a combination of a thin edge, and possibly a little uneven heating. I still have some difficulty differentially hardening 1/8" stock. About the only way I've found to whip it is to do most of my grinding after heat treating, and normailize it prior to hardening.
When I'm dealing with stock that thin, I usually just mark where I want the plunge cuts with a 120 belt, and then heat treat. I does take a bit more time to grind everything after the heat treat, but for me it was one of the only ways I could find to help minimize the warping on the thin stuff. (I still get warpage on about 10% of stufft that thin)