A finely radiused and clean hammer head is essential for quality metal shaping since we only want smooth striking surfaces. That means a body hammer should never be used as you would a regular hammer since that will ruin the surface of the head. Never attempt to work metal with a hammer that looks like the one on top; misuse and the low-grade steel has taken a beating and lost its shape. Major resurfacing is required to restore it. Also, the head should be free of contaminants; you don’t want to pound oils or grease into the steel you’re trying to work.