I have broken innumerable handles on hammers, mauls, axes and sledges, and somehow the replacement handle never fits quite as well as the original. It usually comes loose after a period of use, no matter how hard I drive in the end wedges. My solution to this problem is to use five-minute epoxy to glue the handle to the head. I clean out the hole in the hammer head, fit the new handle to it using a rasp, and then liberally coat both the handle and the hole with the two-part epoxy glue. Then I drive the handle into the hole, set the wooden and steel wedges, and allow the glue 24 hours to cure. The epoxy fills any gaps between the handle and the steel. I’ve never had a replacement handle come loose using this technique.
Craig Stead, Putney, VT