GB/T 2933-2025Vocabulary, designation and marking of wheels and rims for pneumatic tyres (English PDF)

3.2 Wheel Components

3.2.1 rim

The component on the wheel that mounts and supports the tyre.

3.2.2 disc; wheel disc

The supporting component on the wheel between the axle and the rim.

3.2.3 single wheel

A wheel that supports the tyre at one end of the axle.

3.2.4 inset wheel

A wheel with the center plane of the rim located inboard of the spoke mounting surface.

3.8.6 five- or more piece rim

A circlip composed of five or more components, when combined with other components, constitutes a five-piece, six-piece, seven-piece or eight-piece rim.

4.1 Designation

The designation of wheels and rims shall be expressed using numbers and letters in the following order of priority.

a) Nominal diameter of rims.

---Existing rims are represented by the size designation1);

---For new rims used with new tyres, the nominal diameter is expressed in millimeters.

b) Rim construction type (optional).

---The symbol “x” indicates one-piece rims;

---The symbol “-” indicates multi-piece rims.

c) Nominal width of rims.

---Existing rim size designation1);

---For new rims used with new tyres, the nominal width is expressed in millimeters.

d) Rim profile.

One or more letters are used to represent the rim profile on the tyre mounting side.

EXAMPLE. B and J in ISO 4000-2, K in ISO 4209-2, and C, D, E and F in ISO 18804.

The profile marking is typically located after the nominal rim width, but it may also be located before the nominal rim width or located on both sides of the nominal rim width, as shown in the example of the marking on agricultural machinery rims in 4.2.

e) Flange height.

For rims intended for off-road vehicles, the one or several digits (in inches) following the slash “/” in the size designation1) represent the flange height.

This mode of representation is permitted for multi-piece rims.

4.2 Rim Size / Profile Type

The following are examples of existing rim designation.

Passenger vehicles. 13 x 4.5B, 15 x 6J.

Light commercial vehicles. 15 x 5 1/2J, 15-5.5F SDC.

NOTE 1.SDC represents semi-deep groove rim.

Medium / heavy commercial vehicles. 20-7.5, 22-8.0, 22.5 x 8.25.

Agricultural machinery. 28 x W12, 28 x W10H, 26 x DW16, 38 x W18LA.

1) Size designation is based on the inch size.

NOTE 2.“DW” represents a rim with a secondary groove, “L” represents a low flange, and “A” indicates a wide flange radius.

Off-road vehicles. 25-13.00/2.5.

NOTE 3.“/2.5” is the flange height designation.

5.1 Marking of Disc Wheels and Detachable Rims

The marking of disc wheels and detachable rims shall indicate the following information.

a) Rim designation;

b) Identification mark (name, symbol or trademark) of the wheel or rim manufacturer;

c) Date of manufacture;

d) Part number or code of the wheel or rim manufacturer.

5.2 Marking of Retaining Rings and Lock Rings

The retaining rings and lock rings2) shall indicate the following information.

a) Identification mark indicating the rim with which the component can be used;

b) Identification mark of the manufacturer;

c) Date of manufacture.

5.3 Divide Wheels

Both components of the divide wheels shall be marked in accordance with 5.1.

5.4 Height / Legibility

The marking shall be permanently indented or embossed and free of burrs. The typeface shall be at least 3 mm in height and clearly legible.

5.5 Location / Visibility

The marking on wheels and detachable rims shall be visible after the tyre has been assembled and inflated. For disc wheels, the marking may appear on the rim or spokes.

5.6 Additional Markings

2) The retaining ring and lock ring can be disassembled from the rim body. Since their design and development vary from manufacturer to manufacturer, they should not be considered interchangeable.

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