The leather mallet is in my opinion the best tool for striking harden steel. It does not give the recoil through the steel, that can cause it to shatter.
These mallets are not as pretty as the spectacular ones that Klaus makes, but they are also for another use.
With the leather mallet you can beat the shit out of any thing with out hurting the tool.
Some pics of the tool I use.

Tor and Odin are the greatest of gods.