Overview
ISO 4000-2:2021 - "Passenger car tyres and rims - Part 2: Rims" specifies the designation, contour and dimensions of 5° tapered (drop-centre) rims primarily intended for passenger cars. This sixth edition updates valve-hole requirements and corrects a hump circumference tolerance. The standard covers nominal rim-diameter codes (typically 10–30), rim-width and flange types, contour geometry, hump options, and valve-hole design for safe tyre mounting and sealing.
Key topics and technical requirements
- Scope and designation
- Rims are designated by nominal rim-diameter code, nominal rim-width code, and flange type (e.g. 15 × 6 J), per ISO 3911.
- Rim contours and dimensions
- Detailed contour geometry, dimensional tolerances and a rotationally symmetric rim profile (except valve area) are specified (see Figure 1 / Table 2 in the standard).
- Mandatory dimensions include well depth (H), well width (L), bead seat width (P) and flange/edge radii required for mounting and tyre retention.
- Hump options
- Optional flat humps (FH) and round humps (RH) contours are provided with minimum dimensions to support tubeless tyres; humps are required on the vehicle outboard side and recommended on the inboard side.
- Hump circumference and diameter tolerances for each nominal rim code are specified (Table 4; D ± 0.4 mm for rim diameter).
- Valve holes (11,3)
- Valve hole edges on tyre side must be rounded or chamfered; weather-side edges must be burr-free.
- Separate detailed requirements and drawings for snap-in and clamp-in valves: flat sealing surfaces, minimum unbroken inside surface (≥ 0.75 mm or 25% of rim thickness), and rim-thickness limits (1.5–4.0 mm). Recommendations for TPMS snap-in valve compatibility (1.8–4.0 mm) are included.
Applications and who uses this standard
- Wheel and rim manufacturers - ensure rims meet standardized fitment, safety and interchangeability requirements.
- Automotive OEMs and tier suppliers - design and specify rims for new vehicles.
- Tyre manufacturers and fitters - confirm rim geometry for safe mounting, bead seating and tubeless sealing.
- Valve and TPMS developers - design valve stems and mounting features (snap-in/clamp-in) to match rim hole geometry.
- Testing labs, regulators and aftermarket wheel suppliers - verify compliance, perform dimensional checks and certify replacement wheels.
Related standards
- ISO 3911 - Wheels and rims: vocabulary, designation and marking (referenced).
- ISO 9413 - Tyre valves: dimensions and designation (referenced).
- Other parts of the ISO 4000 series cover tyres and rims interactions.
Keywords: ISO 4000-2, passenger car rims, 5° tapered rims, drop-centre rims, rim dimensions, valve hole 11,3, rim designation, tubeless tyres, TPMS.
