Appearances: Episode 703, 1403
Also sometimes spelled a ball peen hammer, this is more of a metal working tool. Since technically, claw hammer's heads are of relatively brittle composition and shouldn't be used for directly striking metal objects such as chisels (nails are much softer than the hammer head, thus are the exception), another tool is needed.
Ball pein hammer heads are tempered to a softer composition and thus are suitable for direct striking of metal tools. Peening rivets is just one example of their suitablility, and was the task performed when it appeared in the below episode.
