Mold and die repairs are made by bonding a piece of .008" thick ferrous ribbon material or .010" or .020" diameter wire or metallic paste / powder to the desired areas on a steel workpiece.

The ribbon material or wire usually is in the annealed state before micro welding, but will be in the hardened state after being bonded in place. The hardness of the micro weld will vary of course, according to what material is used in the repair, which should have the same or similar properties as the workpiece. Stainless steel, nickel alloys, and mold steels, such as P-20, S-7, A-2, and 420 stainless are some of the more commonly repaired materials.