I don't know about other makers, but L.C. Smith hammers are cast from steel.
I mig welded one that had a broken tip. I did not have the other half and made one out of drill rod, heated and shaped it to look like the other side. After being welded I filed and touched it up with Oxpho Blue and filed the cross hatch tip.


This was for my own hammer gun, tried it a few times, and has held up, time will tell if it lasts.

David