BS ISO 3739‑2:2021 pdf – Industrial tyres and rims Part 2: Pneumatic tyres (metric series) on 5 degrees tapered or flat base rims — Load ratings.
1 Scope This document specifies the load ratings of the metric series of pneumatic tyres primarily intended for industrial vehicles for use on prepared surfaces. ISO 3739‑1 deals with designation, dimensions and marking; ISO 3739‑3 deals with rim contours for these tyres. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3739‑1, Industrial tyres and rims – Part 1: Pneumatic tyres (metric series) on 5 degrees tapered or flat base rims – Designation, dimensions and marking ISO 4223‑1, Definitions of some terms used in the tyre industry — Part 1: Pneumatic tyres ISO 5053‑1, Industrial trucks — Vocabulary — Part 1: Types of industrial trucks 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 4223‑1 and ISO 5053‑1 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https://www.iso.org/obp — IEC Electropedia: available at http://www.electropedia.org/ 4 Reference load-carrying capacity The 100 % reference load-carrying capacity is the load corresponding to the load index marked on the tyre. The correlation between load index and tyre load-carrying capacity shall conform to ISO 3739‑1. Reference load-carrying capacities of several versions of the same tyre size (same dimensional and constructional characteristics) shall be based on reference inflation pressures of 550 kPa, 675 kPa, 825 kPa and 1 000 kPa.
5.3 Calculated load Calculated loads from Tables 1, 2, 3, and 4 shall be rounded to nearest 5 kg 5.4 Dual tyre load When fitted in dual formation, the load for the two tyres is twice that for a single tyre. 6 Inflation pressures Operating cold inflation pressures should be agreed between tyre and vehicle manufacturers taking into account not only the tyre load-carrying capacity, but also the operating conditions, the maximum speed, the position of the tyre on the vehicle, service conditions and the construction and characteristics of the vehicle. Cold inflation pressure means the pressure taken with the tyre at ambient temperature; it does not include any pressure build-up due to tyre usage.