ISO 18805:2026

ISO 18805:2026 is an International Standard from ISO that sets classification codes for tyres used on agricultural and forestry tractors and machines. It gives a common tyre nomenclature so tyre makers, machinery builders, distributors, and buyers can identify the tyre purpose and tread type in the same way.

What does ISO 18805:2026 specify?

ISO 18805:2026 specifies the classification codes of tyres for agricultural and forestry tractors and machines. Clause 4 is the core of the document: Table 1 defines tyre purposes, and Table 2 assigns the corresponding classification codes and tread names.

The document is practical rather than prescriptive in a test sense. It is used to name tyres correctly, not to set performance limits.

What are the key requirements of ISO 18805:2026?

ISO 18805:2026 requires users to treat the classification code as a tyre identification code, not as part of the size marking. When the code is used, it shall be clearly separated from the size marking on the tyre. In practice, this avoids confusion between tyre size and tyre service description.

The tyre-purpose definitions matter

ISO 18805:2026 uses Table 1 to define what each tyre is intended to do. The main purpose groups are:

• Tractor drive-wheel tyre - for driven axles on agricultural and forestry tractors, where sustained high torque is expected.
• Tractor steering-wheel tyre - for non-driven axles on agricultural and forestry tractors.
• Implement tyre - for agricultural machines, implements, or trailers that are not intended for sustained high torque service.
• Implement traction tyre - for driven axles on implements or agricultural machinery, identified with I-2 and I-3.
• Implement trailer tyre - for non-driven axles of implements, agricultural machinery, or trailers, identified with I-1, I-4, and I-6.
• Logging and forestry service tyre - a special-design agricultural tyre for forestry use.
• High flotation tyres - larger-volume tyres intended to reduce surface contact pressure.

In practice, these definitions help a buyer or engineer choose the right service category before comparing tread patterns.

The classification codes group tyres by service

ISO 18805:2026 uses Table 2 to group tyres by service type and tread name. The main groups are:

• R - agricultural tractor drive-wheel service
• F - agricultural tractor steering-wheel service, non-traction pattern
• I - agricultural implement service
• G - lawn and garden service
• LS - logging and forestry service
• HF - high flotation service

Each group then has named subtypes such as R-1 regular tread, R-1W wet soil traction tread, R-2 cane and rice deep tread, and R-4 industrial, construction application tread. This gives a shorthand for specifying the tread style needed for soil conditions or machine use.

The code names tell you the intended use

ISO 18805:2026 links each code to a clear tread or service description, such as F-1 agricultural single rib tread, I-3 traction tread, LS-3 deep tread, or HF-4 extra deep tread. In practice, this is what people use when writing tyre specifications, comparing products, or checking that a tyre matches the intended machine task.

What terms does ISO 18805:2026 define?

ISO 18805:2026 relies on the terms in ISO 4223-1, and clause 4 gives the key purpose terms used in the classification.

• Tractor drive-wheel tyre - a tyre for driven tractor axles where high torque is sustained.
• Tractor steering-wheel tyre - a tyre for non-driven tractor axles.
• Implement tyre - a tyre for agricultural machines, implements, or trailers that are not in sustained high torque service.
• Logging and forestry service tyre - a special agricultural tyre designed for forestry application.
• High flotation tyres - tyres with larger volume to lower surface contact pressure.
• Classification code - the service code such as R, F, I, G, LS, or HF used to identify the tyre category.
• Size marking - the tyre size identification, from which the classification code is kept separate.

Who uses ISO 18805:2026?

ISO 18805:2026 is used by tyre manufacturers, agricultural and forestry machinery manufacturers, dealers, and buyers who need a shared naming system for tyre types. It also helps procurement teams and service staff specify replacement tyres correctly and compare products by service category rather than by appearance alone.

What changed in ISO 18805:2026 from the previous edition?

ISO 18805:2026 is the second edition and cancels and replaces ISO 18805:2017. The stated technical change is a modification of the classification codes in Table 2.

Which standards are used with ISO 18805:2026?

ISO 18805:2026 cites ISO 4223-1, Definitions of some terms used in the tyre industry - Part 1: Pneumatic tyres. That reference supplies the general tyre terminology used in the document, so users should read it when they need the accepted industry meanings of the terms.

What does the ISO 18805:2026 document contain?

ISO 18805:2026 is a short, table-driven standard built around classification and nomenclature. It contains one table of tyre-purpose definitions and one table of classification codes and tread names, which together support tyre specification and identification.

The document also states how the code is to be shown relative to the size marking, which matters when marking tyres and writing product descriptions. Its structure is limited to scope, normative references, terms and definitions, and the classification section, so readers can find the naming rules quickly.