ISO 12129 is an International Standard that discusses plain bearings.
ISO 12129‑1 is the first part of the multi-series of documents applicable to tolerances of plain bearings.
ISO 12129‑1 specifies a system of fits applicable to metallic plain bearings used in general engineering for mean relative bearing clearances, ψm, of 0,56 ‰ up to 3,15%.
Note: This system of fits is not applicable to half‑bearings and bushes which, due to their special characteristics, are not measured by diameter but by wall thickness, and which are dimensionally changed on assembly. It is not applicable to profile bore or tilting pad bearings, or to cases where specific tolerances have been established by consideration of the bearing performance at both extremes of clearance.
ISO 12129‑1 on plain bearings is applicable to:
Plain bearings are used for sliding, rotating, oscillating, or reciprocating motion. Plain bearings support and guide moving components inside the engine. The objective of plain bearings is to prevent wear of the machine's support points, which would occur if the shafts were to roll directly on the structure.
ISO 12129‑1 has been established because it is not possible to use the ISO deviations given in ISO 286‑1 and ISO 286‑2 to develop clearance fits which correspond to the requirements of plain bearing engineering for approximately uniform mean relative bearing clearances for all nominal size ranges.
ISO 12129‑1 walks you through best industry guidance on tolerance intervals, ranges of nominal dimensions, limit deviations and minimum and maximum clearances, for consistent quality and performance of bearings.
If you are a manufacturer, you can demonstrate the reliability and quality of your products by meeting the requirements in accordance with ISO 12129-1.
ISO 12129-1