320gr. (Surgical Hammer) Used to manually impart a force (i.e., strike) on another device (e.g., a chisel). Available in a variety of designs and materials, the shaft is typically made of metal (e.g., chromed iron or high-grade stainless steel), but can be made of synthetic materials (e.g., tufnol), and tapers distally to the head. The head is typically a solid, cylindrical shape normally being double-ended and made of solid (iron/steel) or shock absorbing materials (e.g., rubber, plastic, or tufnol)..