If I am reading the (somewhat humerous) translation correctly, they are being made in a single heat , within a very narrow temperature range, to produce a fine grained steel. This will make them very tough, fairly hard, and very uniform.
The only thing I suppose would be a no-no is hitting another hardened steel object (like your anvil) with them...
I am thinking 'chisel hammer' is more of a poor translation than a specific use (ie a hammer for striking another tool)
The hammers you don't want to use for striking another tool are the ones that are soft inside and hardened only on the outside.
