The KA hammer will clamp and hold stock for twisting. The down force of the ram is 500 PSI at 100 PSI of input air. Spring tooling is used to ornament stock before twisting to give complicated effects like rope or wood grain.
Forge welding is a stumbling block for many smiths as there is little time to position the hot material, drop the tongs, reach for the hammer and strike while the iron is hot. The KA hammer allows both hands to be used to hold the material while the weld is made.