GB/T 20786-2025Rubber track (English PDF)

3.1 Rubber track

An annular rubber belt fitted onto the running gear of agricultural machinery, construction machinery, transport vehicles to assist movement, which is made of rubber vulcanized with metal or fiber materials.

3.2 Tread rubber

The outer rubber layer of a rubber track that faces the ground when moving.

3.3 Roller rubber

The inner rubber layer of a rubber track that faces the wheel in the wheel system of the running gear when moving.

3.4 Metal core

The metal or other material skeleton in a toothed rubber track that transmits power, provides guidance, offers lateral support.

3.5 Strength layer

The skeleton layer in a rubber track that bears tension and transmits power, typically made of materials such as steel wire cord (fiber rope).

3.6 Guide lug

The raised portion of a friction-type rubber track that guides movement.

3.7 Drive lug

The raised portion of a wheel-hole type rubber track that transmits power and provides guidance.

3.8 Pitch

The center-to-center distance between two adjacent repeating units (two metal cores, two guide lugs, or two drive lugs) of a rubber track.

4.1 Classification and structure

Rubber tracks are classified into the following three categories according to their drive method, as shown in Table 1.

- Toothed rubber tracks, denoted by CRT;

- Wheel-hole type rubber tracks, denoted by KRT;

- Friction-type rubber tracks, denoted by MRT.

4.2 Marking

Rubber tracks are marked in the following order.

Rubber track type code - This document number - Specification [Width (mm) × Pitch (mm) × Number of sections - Applicable maximum machine mass (t)]

Example: A toothed rubber track with a track width of 400 mm, a pitch of 72.5 mm, a number of sections of 80, an applicable maximum machine mass of 5 t is marked as: CRT-GB/T 20786-400×72.5×80-5.

5.1 Specifications and dimensions

Specifications and dimensions and permissible deviations shall conform to the provisions of Table 2.

5.2 Appearance quality

Rubber tracks are not allowed to have exposed steel wires (or fiber ropes), surface impurities, spongy texture, delamination, cracks, or splits. There are no visible scars or blisters with a diameter greater than 10 mm and a depth greater than 2 mm are allowed.

For visible scars or blisters with a diameter greater than 10 mm and a depth greater than 2 mm, the quantity shall be not more than 3 places for rubber track which has a center circumference of not more than 5 m; or it shall be not more than 5 places for rubber track which has a center circumference of more than 5 m.

5.3 Performance requirements

5.3.1 Rubber materials

The physical and mechanical properties of the rubber materials used for rubber tracks shall conform to the specifications in Table 3. […]