INTERN MPAPS H-1 PDF

SCOPE

This specification covers the Corporation’s requirements for structural parts produced from powdered metals. The term “P/M parts” is used throughout this specification as the designation for powdered metal parts.

Note: Requirements for all powdered metal bearings and bushings with low to medium density, in which porosity and self-lubrication are paramount, are classified as porous sintered metal bearings and are covered in MPAPS C-5, Bearing and Bushing Alloys.

Restricted Chemical Substances

All product supplied to the requirements of this specification must comply with the requirements of MPAPS B-50.

APPLICATION

Powder metal (P/M) structural parts covered herein refer to machine components whose load carrying capability, strength, and density are the major design factors. For applications involving combined functions such as structural and self-lubrication or wear, a Materials Engineer should be consulted.

Part Development and Specification (Structural Application)

A complete material specification for a P/M part cannot be written at the proposal stage. The engineer must refer to the design guide in “Appendix - General Information” for detailed recommendations regarding the development of an effective material specification.

The design engineer should make a tentative material choice in cooperation with a P/M parts supplier and/or Materials Engineer using the materials listed in Table I. This table, based upon MPIF Standard 35, describes materials in terms of composition and strength. Since limits for the other mechanical properties cannot initially be specified, some typical mechanical properties for test bars are shown in “Appendix - General Information” as a guide. Additional mechanical properties and design information are found in other MPIF or ASTM specifications. See “Mechanical Property Requirements”, Section 6.2.

Prototype parts will be “de-rated” to assist in the development of minimum engineering properties for the specification of the proposed parts. In some cases, the de-rating will be done by specifying prototype parts with a lower strength value than the minimum specified for production parts. In other cases, the de-rating will be done by specifying prototype material density lower than the minimum proposed for production parts.