ISO 4251-1:2019

This document establishes the designation in use and the dimensions of code designated tyres in diagonal construction (ply rating marked series) for agricultural tractors, trailers and machines.
Tyre load ratings are given in ISO 4251-2.
NOTE Code designated diagonal tyres (ply rating marked series) for construction applications (industrial tractors), identified by the classification code R-4, as specified in ISO 18805, or by suffix 'IND' are covered by ISO 13442.
Code designated tyres in radial construction for drive wheels of agricultural tractors are covered by ISO 8664.
Code designated diagonal tyres (ply rating marked series) for forestry machines, identified by the classification code LS, as specified in ISO 18805, are covered by ISO 18807.