ISO 20015:2017

Spherical plain bearings - Method for the calculation of static and dynamic load ratings

ISO 20015:2017 specifies methods of calculating the static load rating and the dynamic load rating for spherical plain bearings within the size ranges shown in ISO 12240-1, ISO 12240-2 and ISO 12240-3. Rod ends according to ISO 12240-4 are excluded.

Rotules lisses — Méthode de calcul des charges statiques et dynamiques de base

General Information

• Status: Published
• Publication Date: 16-Aug-2017
• ICS: 21.100.20 - Rolling bearings
• Technical Committee: ISO/TC 4/SC 8 - Load ratings and life
• Drafting Committee: ISO/TC 4/SC 8 - Load ratings and life
• Current Stage: 9093 - International Standard confirmed
• Start Date: 13-Jan-2023
• Completion Date: 13-Dec-2025

Overview

ISO 20015:2017 - "Spherical plain bearings - Method for the calculation of static and dynamic load ratings" specifies standardized methods to calculate static load ratings and dynamic load ratings for spherical plain bearings within the size ranges covered by ISO 12240‑1, ISO 12240‑2 and ISO 12240‑3. Rod ends (ISO 12240‑4) are explicitly excluded. The standard defines terms, symbols and calculation procedures for radial, angular contact radial and thrust spherical plain bearings, and includes informative annexes explaining factors and a worked calculation example.

Key topics and requirements

• Scope and definitions: clear definitions for static and dynamic conditions, including static radial/axial and dynamic radial/axial load ratings.
• Calculation methods: prescriptive formulae for:
  • Radial spherical plain bearings (static and dynamic)
  • Angular contact radial spherical plain bearings (static and dynamic)
  • Thrust spherical plain bearings (static and dynamic)
• Geometrical parameters: calculations use bearing dimensions such as bore (d), outer diameter (D), sphere diameter and ring widths (B, C, S1, S2) as defined in ISO 12240 series.
• Material and design factors (f): the standard requires use of factors (f0r, fr, f0a, fa) that depend on sliding materials, surface treatments, heat treatment and design features (seals, lubrication grooves). These factor values are not defined in ISO 20015 and should be obtained from the manufacturer.
• Annexes: Annex A explains the influence of materials and design on the f factors; Annex B provides a calculation example to illustrate application.

Applications and users

ISO 20015:2017 is practical for:

• Bearing manufacturers - to supply standardized load rating data and to define the f factors for product ranges.
• Design and mechanical engineers - to size and specify spherical plain bearings for machines, hydraulic cylinders, pivots and articulating joints where spherical plain bearings are used.
• Procurement and quality teams - to compare supplier data and ensure compliance with ISO load‑rating calculation methods.
• Standards and testing bodies - for harmonized reporting of static and dynamic load capacities.

Practical uses include generating consistent static and dynamic load rating values for product datasheets and engineering specifications; engineers use these ratings to determine allowable loads and to ensure compatibility between bearing geometry and application loads.

Related standards

• ISO 12240‑1, ‑2, ‑3 - dimensional definitions for radial, angular contact radial and thrust spherical plain bearings
• ISO 12240‑4 - rod ends (excluded from ISO 20015 calculations)
• ISO 6811 - vocabulary for spherical plain bearings

Keywords: ISO 20015:2017, spherical plain bearings, static load rating, dynamic load rating, ISO 12240, bearing load calculation, radial bearings, thrust bearings, angular contact bearings.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20015
First edition
2017-08
Spherical plain bearings — Method for
the calculation of static and dynamic
load ratings
Rotules lisses — Méthode de calcul des charges statiques et
dynamiques de base
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and units . 2
5 Radial spherical plain bearings . 3
5.1 Static radial load rating . 3
5.2 Dynamic radial load rating . 3
6 Angular contact radial spherical plain bearings . 4
6.1 Static radial load rating . 4
6.2 Dynamic radial load rating . 4
7 Thrust spherical plain bearings . 5
7.1 Static axial load rating . 5
7.2 Dynamic axial load rating . 5
Annex A (informative) Explanations of factors for the calculation of load ratings .7
Annex B (informative) Calculation example . 8
Bibliography . 9
Foreword
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This document was prepared by Technical Committee ISO/TC 4, Rolling bearings, Subcommittee SC 8,
Load ratings and life.
iv © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 20015:2017(E)
Spherical plain bearings — Method for the calculation of
static and dynamic load ratings
1 Scope
This document specifies methods of calculating the static load rating and the dynamic load rating for
spherical plain bearings within the size ranges shown in ISO 12240-1, ISO 12240-2 and ISO 12240-3.
Rod ends according to ISO 12240-4 are excluded.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 6811, Spherical plain bearings — Vocabulary
ISO 12240-1, Spherical plain bearings — Part 1: Radial spherical plain bearings
ISO 12240-2, Spherical plain bearings — Part 2: Angular contact radial spherical plain bearings
ISO 12240-3, Spherical plain bearings — Part 3: Thrust spherical plain bearings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12240-1, ISO 12240-2,
ISO 12240-3 and ISO 6811 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 Static conditions
3.1.1
static load rating
maximum load that the spherical plain bearing can accommodate at room
temperature without inadmissible deforming or damage of the sliding surfaces, when there is no
relative movement between the sliding contact surfaces
3.1.2
static radial load rating
C
0r
st
...