SE JT332RB Steel and Nylon 2-in-1 Round Block with Rubber Base, 3" All purpose bench block anvil tool set for metal forming, flattening, metalsmithing, silversmithing and more Materials: steel, nylon and rubber blocks Metal block provides a flat smooth surface for flattening Nylon block is used with softer steels or for delicate work Rubber base that absorbs shock and holds the steel or nylon block in place