Scope

Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take

precedence.

1.1 Purpose/Material Description. This material specification applies to low to medium alloy modified American

Iron and Steel Institute (AISI) AISI P20 Tool Steel, as defined in ASTM A681 , produced through various melting,

forging, and heat treatment manufacturing processes.

1.2 Symbols. Not applicable.

1.3 Applicability. Modified AISI P20 Tool Steel is used in the construction of cavity and core tooling used for the

thermoplastic injection molding. GM Tool Steel Grades in this standard are specified by surface hardness,

hardenability, microstructure, chemistry, physical properties, and quality requirements to achieve a balance of

machinability, thermal conductivity, fracture toughness, corrosion resistance, weldability, wear resistance, ability to

polish, ability to etch, and core strength which are all critical characteristics of injection mold tools.

1.3.1 This standard addresses Steel Supplier and Material Requirements for modified AISI P20 Tool Steel and are

part of the Steel Supplier Approval Process. After successful completion of the submission per Appendix A, A1 and

GM approval, all sections of this standard are intended to apply to production forgings used to make injection molds.

1.4 Remarks. Thermoplastic injection mold tooling design, construction, and validation requirements can be found

in GMW1 5850. This specification is intended to support technical problem solving when considering the mill origin

of tool steel, metallurgical certification data, and production processing only and will not specify tool build

requirements.