This is an idea I instituted at school to avoid peening over the ends of the Bridgeport drawbars. We use double end box wrenches as shown below on our B'ports and we had the usual problem of the ends of the draw bars getting damaged.
The brass hammer heads we made fine nicely into the unused end of the box wrench and are made as sketched below. I had a box of 1/2 - 13 set screws and used them to tie the two parts together with a drop or two of Loctite.
I used hexagonal brass since I had some in the scrap bin but round stock could also be used. The brass has enough geft to it to strike the drawbar smartly and has eliminated damage to the drawbars.
