That almost looks like cast iron. I find it hard to believe the maker would have used that material in this application but maybe it was done to get a net shape part within a shorter cycle time. They overbuilt on the assumption it wouldn't break within reasonable limits. Somehow, your hammer developed a stress riser that propagated with time.
If it is steel, it can be successfully welded as Jr described. I have welded large driveshafts that twisted in half using similar techniques and they held up. |