The hammer wrench is just a chunk of bronze (I think--maybe Red Brass) turned to size then bored for a socket to fit into. I was trying for a nice press fit--but, typical of my latest boring attempts, it was way too tight the first try then slipped right in the next. A good dose of super-glue is holding it in place and since it sees very little torque it will work fine. The handle is just some cheap home-depot steel turned down, threaded 3/8"-16 for attaching to the head, then knurled. The end near the head is just barely less than 1/2", that let me spot face the head with a 1/2" endmill then drill and tap for the handle. Some blue loctite holds it together. Try to locate the handle so the head is balanced or a tad heavy on the hammer-end.