ISO/TC 123/SC 3 - Dimensions, tolerances and construction details

This document specifies tolerances, design features and test methods for thin-walled half bearings with integral flange up to an outside diameter of Do = 250 mm and without flange up to an outside diameter of Do = 500 mm. Due to the variety of design, it is, however, not possible to standardize the dimensions of the half bearings. Half bearings according to this document are predominantly used in reciprocating machinery and consist of a steel backing and one or more bearing metal layers on the inside. In reciprocating machinery, flanged half bearings can be used in connection with half bearings without flange. Alternatively, to serve as a flanged half bearing, it is possible to use a half bearing without flange together with two separate half thrust washers according to ISO 6526, or a half bearing with assembled flanges. NOTE All dimensions and tolerances are given in millimetres.

This document specifies design characteristics for side flange bearings for the size range 9 to 28, as well as design characteristics for shafts. It is applicable to side flange bearings used mainly in electrical and turbo engineering industries.

This document specifies design characteristics for pillow blocks for size ranges 9 to 28 and 35 to 71, as well as design characteristics for shafts. It is applicable to pillow blocks used mainly in electrical and turbo engineering industries.

This document specifies dimensions for lubrication holes, grooves and pockets for bearing bushes. These dimensions can be entered, for example on drawings, using the designation examples. Their use depends in particular on the specific operating conditions. In addition, it enables the user to assign the different types of lubricant feed and distribution to solid and steel-backed plain bearing bushes made of copper alloys, aluminium alloys, thermosetting plastics, thermoplastics or artificial carbon. NOTE Different types of lubricant feed and distribution for plain bearing bushes made of sintered metals have not been specified due to the fact that these bushes are soaked with lubricant. Plain bearing bushes made of artificial carbon are not lubricated with oil or grease.

This document specifies design characteristics for centre flange bearings for the size range 9 to 28, as well as design characteristics for shafts. It is applicable to centre flange bearings used mainly in electrical and turbo engineering industries.

This document specifies tolerances on form and position as well as the surface roughness of shafts, flanges and thrust collars as used in plain bearing units. It is applicable to journal or thrust plain bearing units or to a combination of both, installed either horizontally or vertically. This document is not applicable to crankshaft bearing units in combustion engines.

This document provides requirements and guidance on lubricant supply arrangements and monitoring for liquid-lubricated bearings (plain bearing assemblies) such as those specified in ISO 11687 (all parts). This document is intended to assist the design of oil-based lubrication systems for hydrodynamic plain bearings mainly to be used in large-scale rotating machinery for power generation, industry and transportation. This document focuses on the most important requirements and characteristics of lubricant supply arrangements and monitoring for plain bearings. Additional standards such as ISO 10438‑1, ISO 10438‑2 and ISO 10438‑3 would be needed to design complete low-pressure or high-pressure lubrication systems, along with their corresponding components. Wherever this document specifies a particular form of solution, whether design or operation, different solutions can be selected provided they are justified by engineering assessment or reference to similar systems already in operation.

This document 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 ?. Other clearance ranges can be used depending upon the requirements in specific applications. 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. This document is applicable preferably to rotating machine parts and shafting, but it can be used similarly in other ranges of application.

This document specifies dimensions and tolerances for cylindrical and flanged bushes with internal diameter, d1, in the range 6 mm to 200 mm. It applies to solid mono‑metal copper alloy bushes to be used as plain bearings with and without oil holes and oil grooves.

This document specifies a range of ring type thrust washers for general purpose use with wrapped bushes as specified in ISO 3547 (all parts). It applies to thrust washers having inside diameters from 6 to 80 mm. NOTE It is not expected that all the sizes listed will be available from stock but the standardization of sizes is aimed at making economies in tooling costs.

This document specifies the dimensions and designations of cylindrical and flanged wrapped bushes made of mono and multi-layer bearing material for plain bearing applications.

ISO 6526:2017 specifies the main features and tolerances for pressed bimetallic half thrust washers having an outside diameter up to 160 mm. NOTE 1 All the linear dimensions and tolerances are expressed in millimetres. NOTE 2 The main dimensions for the half thrust washers are not the subject of this document.

ISO 3547-4:2017 gives specifications for solid and multi-layer bearing materials, such as those used for wrapped bushes in accordance with the other parts of ISO 3547.

ISO 3547-2:2017 specifies the test data for outside and inside diameters of wrapped bushes made of mono and multi-layer bearing material for plain bearing applications. It also specifies test designations. Since the wall thickness of the bush is measured in the free condition, no special test data are required for this on the drawing (see ISO 3547‑5 and ISO 3547‑6). NOTE Depending on the manufacturing method, the back of the bushes can show isolated light depressions and, similarly, bushes with lubrication holes, grooves and bore indentations can show distortion. It is therefore suggested to measure the wall thickness away from these areas.

ISO 3547-3:2017 specifies dimensions of lubrication holes, grooves and bore indentations on wrapped bushes made of mono and multi-layer bearing material for plain bearing applications. NOTE Wrapped bushes with lubrication holes, grooves or bore indentations in accordance with this document can be ordered with dimensions in accordance with ISO 3547‑1 and made from materials in accordance with ISO 3547‑4.

ISO 3548-1:2014 specifies tolerances, design features, and test methods for thin-walled half bearings with integral flange up to an outside diameter of Do = 250 mm and without flange up to an outside diameter of Do = 500 mm. Due to the variety of design, it is, however, not possible to standardize the dimensions of the half bearings. Half bearings according to ISO 3548-1:2014 are predominantly used in reciprocating machinery and consist of a steel backing and one or more bearing metal layers on the inside.

ISO/TR 27507:2010 gives recommendations for automotive crankshaft bearing environments. It specifies the various dimensions and conditions that most engine manufacturers can achieve with current production machinery in order to produce crankshaft bearing environments, which, generally, do not lead to bearing problems.

ISO 3547-4:2006 gives specifications for solid and multi-layer bearing materials, such as are used for wrapped bushes in accordance with the other parts of ISO 3547.

ISO 3547-3:2006 specifies dimensions of lubrication holes, grooves and bore indentations on wrapped bushes made of solid and multi-layer bearing material for plain bearing applications.

ISO 3547-1:2006 specifies the dimensions and designations of cylindrical and flanged wrapped bushes made of solid and multi-layer bearing material for plain bearing applications.

ISO 3547-2:2006 specifies the test data for outside and inside diameters of wrapped bushes made of solid and multi-layer bearing material for plain bearing applications. It also specifies test designations.

This International Standard specifies dimensions for lubrication holes, grooves and pockets for bearing bushes. These dimensions can be entered, e.g. on drawings, using the designation examples. Their use depends in particular on the specific operating conditions. In addition, it enables the user to assign the different types of lubricant feed and distribution to plain bearing bushes made of copper alloys, thermosetting plastics, thermoplastics or of artificial carbon. NOTE Different types of lubricant feed and distribution for plain bearing bushes made of sintered metals have not been specified due to the fact that these bushes are soaked with lubricant. Plain bearing bushes made of artificial carbon are not lubricated with oil or grease.

Specifies tolerances on form and position as well as the surface roughness of shafts, flanges and thrust collars as used in plain bearing units. Applicable to journal or thrust plain bearing units or to a combination of both, installed either horizontally or vertically. Not applicable to crankshaft bearing units in combustion engines.

Specifies a system of fits applicable to metallic plain bearings used in general engineering. Not applicable to half-bearings and bushes which are not measured by diameter but by wall thickness, and which are dimensionally changed by assembly. Applicable preferably to rotating machine parts and shafting, but it may be used similarly in other ranges of application.

Specifies dimensions for lubrication holes, grooves and pockets for bearing bushes. Enables the user to assign the different types of lubricant feed and distribution to plain bearing bushes made of copper alloys, thermosetting plastics, thermoplastics or of artificial carbon.

Specifies design characteristics (classification, dimensions, materials, designation) for pillow blocks for the size ranges 9 to 28 and 35 to 71, as well as design characteristics for shafts. Is applicable to pillow blocks used mainly in electrical and turbo engineering industries.

Specifies design characteristics (classification, dimensions, materials, designation) for side flange bearings for the size range 9 to 28, as well as design characteristics for shafts. Is applicable to side flange bearings used mainly in electrical and turbo engineering industries.

Specifies design characteristics (classification, dimensions, materials, designation) for centre flange bearings for the size range 9 to 28, as well as design characteristics for shafts. Is applicable to centre flange bearings used mainly in electrical and turbo engineering industries.

Specifies dimensions and tolerances for cylindrical and flanged bushes with internal diameter in the range 6 mm to 200 mm. Applies to solid mono-metal copper alloy bushes to be used as plain bearings with and without oil holes and oil grooves.

Specifies two methods of checking the measuring equipment and gauging tools necessary for measuring the peripheral length (or nip or crush) of thin-walled half-bearings that are flexible and, in the free condition, do not conform to a cylindrical profile. Method A is based on applying the checking load via the measuring head to one joint face, method B on applying two (different) checking loads via the measuring head to both joint faces. Annexes A to D deal with the determination of the correction factors, Annex E describes tests and calculation of repeatability, reproducibility and comparability.

Specifies the main features and tolerances for pressed bimetallic half thrust washers having an outside diameter up to 160 mm. Gives symbols, tolerances for diameters and for heights, total thickness, locating lug, grooves, joint faces, fillet radii, chamfers, flatness as well as surface roughness.

Specifies a range of thrust washers for general purpose use with wrapped bushes. Applies to thrust washers having inside diameters from 6 to 80 mm. It ist not expected that all the sizes listed will be available from stock but adoption of standard sizes should lead to economies in tooling costs.