1 Material: Bearing steel.Smooth surface,wear resistance and keep your hands clean. 2 Quantity: 20pcs per set. Diameter:6mm. Length:60mm. 3 Easy To Press Into Materials Such As Copper,Aluminum,Silver, Pewter,Wood, Alkeme, Brass, Nickel, and Leather. 4 Easy to use and operate-How to use: Put the material into the plaster mold bowl By welding machine suit or tiger s. 5 Can be used to stamp, punch and embellish metal, jewelry, watches, crafts,ect.