Make a Two Bladed Wallet Knife from a Hack Saw Blade

Step 4 Grind the teeth off the cutting edge.

Grind the teeth off the cutting edge. The trick here is to only just grind off the teeth and no more as this is were the steel is the hardest and will keep the best edge. Note water dripping off blade: Keep the blade cool! or you will take the temper out and it will not keep an edge when you sharpen it.