UNS #T20819

H19, equivalent to 879, is a hot work tool and die steel known for its exceptional resistance to shock and abrasion at high temperatures. This steel exhibits good toughness as well as excellent resistance both to heat checking and softening at high temperatures.

Type Analysis

  • Carbon (Nominal) 0.4
  • Phosphorus (Maximum) 0.3
  • Tungsten (Nominal) 4.25
  • Manganese (Maximum) 0.3
  • Chromium (Nominal) 4.25
  • Cobalt (Nominal) 4.25
  • Molybdenum (Nominal) 0.45
  • Iron (Nominal) Balance
  • Vanadium (Nominal) 2.1


CarTech No. 879 should be considered for applications in hot extrusion dummy blocks for copper or brass, permanent molds for brass casting, hot forging die inserts, hot work dies, hot press dies for both steel and brass, hot punch tools, valve extrusion die rings and inserts, forging dies, and hot extrusion die inserts for steel.

Applicable Specifications

  • ASTM A681





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