These hammers are used for a number of reasons. One use of this hammer is to work harden it, which means you will harden the metal. Any time you hammer, bend, or stretch metal, you are making it harder. So a rawhide hammer is helpful for his because it won’t mark your metal. Another use for a rawhide hammer is to just flatten a piece of metal. For example, maybe you cut out a shape, like a metal star, using tin snips, and your star is no longer flat. You can use this hammer to flatten it out again.
