Extrusion dies

STP 12 is a cobalt-based alloy known for its excellent wear resistance, high-temperature strength, and corrosion resistance. It is often used in applications requiring high-speed machining, such as manufacturing extrusion dies. STP 12 is also highly resistant to galling, a type of wear caused by adhesion between sliding surfaces.

The extrusion dies made of cobalt alloy can maintain a very good hardness and toughness at even 800℃ high temperature. The chemical compositions are as follows.

Cobalt Alloy chemical composition

• STP 1  C: 2.2～2.8%, Mn: -, Si: ≤2.0%, Cr: 29.0～33.0%, Ni: ≤3.0%, Mo: ≤1.0%,  W: 11.0～14.0%, Co: Bal., Fe: ≤3%
• STP 3  C: 2.0～2.7%, Mn: ≤1.0%, Si: ≤1.0%, Cr: 29.0～33.0%, Ni: ≤3.0%, Mo: -,  W: 11.0～14.0%, Co: Bal., Fe: ≤3%
• STP 4  C: 0.8～1.3%, Mn: ≤1.0%, Si: ≤1.5%, Cr: 28.0～32.0%, Ni: ≤3.0%, Mo: ≤1.5%,  W: 12.5～15.5%, Co: Bal., Fe: ≤3%
• STP 6  C: 0.9～1.4%, Mn: ≤1.0%, Si: ≤1.5%, Cr: 27.0～31.0%, Ni: ≤3.0%, Mo: ≤1.5%,  W: 3.5～5.5%, Co: Bal., Fe: ≤3%
• STP 12  C: 1.1～1.7%, Mn: ≤1.0%, Si: ≤1.0%, Cr: 28.0～32.0%, Ni: ≤3.0%, Mo: -,  W: 7.0～9.5%, Co: Bal., Fe: ≤3%
• STP 19  C: 1.5-2.0%, Mn: ≤1.0%, Si: ≤1.0%, Cr: 29.5～32.5%, Ni: ≤3.0%, Mo: -,  W: 9.5～11.5%, Co: Bal., Fe: ≤3%
• STP 20  C: 2.2～3.0%, Mn: -, Si: ≤2.0%, Cr: 25.0～29.0%, Ni: ≤3.0%, Mo: ≤1.0%,  W: 14.0～19.0%, Co: Bal., Fe: ≤3%

The abutment, rings, etc., spare parts made of Inconel 718, H13, and extrusion machine carbides are also available.