Due to the greater alloy content of these steels they provide good toughness and abrasion resistance. Such steels are termed through-hardened as they undergo specific heat treatments after machining to harden the matrix. The high alloy content makes weld repair once a tool steel screw is worn nearly impossible and for this reason worn screws are discarded. Tungsten carbide coating is an option to replace up to .025” (.60 mm) total wear by thermal spray buildup on the top of screw flights. This is a proven option that will result in two to three times more useful life from such a repaired tool steel feedscrew.