Bench vises are generally sold with steel jaws. For many applications — knife making, for instance — there’s an advantage in having jaws made from softer materials so as not to mar the work being put in the vise. In this video knifemaker Walter Sorrells makes some replacement jaws on a CNC milling machine.
Tactix Armory: http://www.tactixarmory.com
Sword making videos: http://www.waltersorrellsblades.com
Walter’s Instagram: walterstactix
Tactix Armory Instagram: tactixarmory