1.1 This specification covers porous metallic sleeve, flange, thrust, and spherical iron-base bearings that are produced from mixed metal powder utilizing powder metallurgy (PM) technology and then impregnated with oil to supply operating lubrication.

1.2 Included are the specifications for the chemical, physical, and mechanical requirements of those ferrous PM materials that have been developed and standardized specifically for use in the manufacture of these self-lubricating bearings.

1.3 This specification accompanies Specification B 438/B 438M that covers the requirements for Bronze-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated).

1.4 Typical applications for iron-base bearings are discussed in Appendix X1.

1.5 Commercial bearing dimensional tolerance data are shown in Appendix X2, while engineering information regarding installation and operating parameters of PM bearings is included in Appendix X3. Additional useful information on self-lubricating bearings can be found in MPIF Standard 35 (Bearings) and the technical literature.

1.6 With the exception of density values for which the g/cm³ unit is the industry standard, the values stated in inch-pound units are to be regarded as standard. The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

1.7 The following safety hazards caveat pertains only to the test methods described in this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.