Self-Lubricating Bearings & Bushings

MPIF Standard 35 is issued to provide the design and materials engineer with the information necessary for specifying powder metallurgy (PM) materials that have been developed by the PM parts manufacturing industry. This section of Standard 35 deals with self-lubricating bearings and bushings made by the powder metallurgy process. A bearing may be defined as a machine part in which another component such as a journal or rod turns or slides. A bushing is normally a removable cylinder used to control the size of an opening or to resist abrasion or to serve as a guide. This section does not apply to materials for PM structural, powder forged (PF) steel or metal injection molded (MIM) parts or products which are covered in separate sections of MPIF Standard 35. The same materials may appear in more than one section depending upon their common use, e.g., some bearing materials may also be used in structural applications and vice versa. Each section of this standard is divided into subsections based on the various types of PM materials in common commercial use within that section. Notes at the beginning of each subsection discuss the characteristics of that material. Users of this standard should make a determination as to the availability of any referenced material.

The use of any MPIF Standard is entirely voluntary. MPIF Standards are issued and adopted in the public interest. They are designed to eliminate misunderstandings between the manufacturer and the purchaser and to assist the purchaser in selecting and obtaining the proper material for a particular product. Existence of MPIF Standards does not in any respect preclude any member or non-member of MPIF from manufacturing or selling products that use materials or testing procedures not included in MPIF Standards. Other such materials may be commercially available.

By publication of these Standards, no position is taken with respect to the validity of any patent rights nor does MPIF undertake to ensure anyone utilizing the Standards against liability for infringement of any Letters Patent or accept any such liability.

Neither MPIF nor any of its members assumes or accepts any liability resulting from use or non-use of any MPIF Standard. In addition, MPIF does not accept any liability or responsibility for the compliance of any product with any standard, the achievement of any minimum or typical values by any supplier, or for the results of any testing or other procedure undertaken in accordance with any Standard.

MPIF Standards are subject to periodic review and may be revised. Users are cautioned to refer to the latest edition. New, approved materials and property data may be posted periodically on the MPIF Website. Between published editions, go to to access data that will appear in the next printed edition of this standard.

Both the purchaser and the manufacturer should, in order to avoid possible misconceptions or misunderstandings, agree on the following conditions prior to the manufacture of a PM part: minimum strength value, grade selection, chemical composition, proof testing, typical property values and processes that may affect the part application.

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