Tekton Dead Blow Hammers contain round steel shot inside the head to reduce post-strike rebound and allow for better-controlled hits to the workpiece.) The striking faces on the hammers are made of 4140 chromium-molybdenum steel that's heat-treated to 52 HRC. The jackets of the hammers are made from a hot cast polyurethane that's highly resistant to chipping, cracking, and tearing.