Overview
ISO 3739-3:2021 - "Industrial tyres and rims - Part 3: Rims" defines the principal requirements for rims used with industrial tyres, focusing on 5-degree tapered and flat base rims intended for industrial vehicles operating on prepared surfaces. This third edition (2021) updates rim diameter coding (adds codes larger than 15) and clarifies designation, marking and rim profile guidance for metric-series industrial tyres and rims.
Key topics and requirements
- Scope and purpose: Specifies main requirements for rim contours, size designation and marking, and rim diameters for industrial applications.
- Rim types covered: 5-degree tapered bead seat rims and flat base rims; includes one-piece, multi-piece and drop-centre designs.
- Designation and marking: Rim marking and designation follow ISO 3911 (vocabulary, designation and marking).
- Rim profiles and dimensions: Profiles and minimum contour envelopes are given in Tables 1–3 and detailed in Annex A (figures and contour tables).
- Rim profiles are independent of rim diameter (no profile change tied to diameter).
- Flange widths include edge radius; flange beyond the minimum width must not exceed the flange highest point.
- Rims shall have a 5-degree tapered bead seat where specified.
- Specified rim diameter: Table 3 lists nominal rim diameter codes and corresponding specified diameters (with tolerances intended for tyre design purposes; rim measurement method noted).
- Informative annex: Annex A provides the size range and detailed rim contours for existing rim profiles.
Applications and users
ISO 3739-3:2021 is used by:
- Tyre and rim manufacturers - to design and mark compatible rims and ensure tyre/rim fit.
- Vehicle OEMs and fleet managers - for specification and procurement of rims for forklifts, warehouse trucks and other industrial handling equipment.
- Design and engineering teams - to verify rim profiles, flange and bead-seat geometry for product development.
- Testing laboratories and conformity assessors - to check marking, dimensions and tolerances against the standard.
- Purchasing/specification professionals - to reference standardized rim codes and reduce interchangeability issues.
Practical benefits include improved tyre-to-rim compatibility, clearer procurement specifications, safer mounting practices, and easier international trade of industrial tyres and rims.
Related standards
- ISO 3739-1 - Pneumatic tyres (metric series): designation, dimensions and marking
- ISO 3739-2 - Pneumatic tyres: load ratings
- ISO 3911 - Wheels and rims: vocabulary, designation and marking (normative reference)
- ISO 10499-1 and ISO 18804 - related tyre and rim designation and rim references
Keywords: ISO 3739-3:2021, industrial tyres and rims, rims, 5-degree tapered rims, flat base rims, rim designation, rim profiles, rim marking, specified rim diameter.