BS ISO 8664:2018 pdf download

BS ISO 8664:2018 pdf download.Tyres for agricultural tractors and machines — Code- designated and service-description marked radial drive-wheel tyres
1 Scope
This document specifies the marking, dimensions, load ratings and reference speeds for code-designated agricultural tractor drive-wheel tyres with service description (load index and speed symbol).
It applies to tyres of radial construction in the speed categories 40 km/h (speed symbol A8), and 50 km/h (speed symbol B).
NOTE Code designated series of:
— diagonal (ply rating marked) tyres for agricultural tractors and machines are specified in ISO 4251-1 and ISO 4251-2;
— tyres for logging and forestry machines are specified in ISO 18807 1) ;
— tyres for construction/industrial tractors are specified in ISO 13442.
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 4223-1, Definitions of some terms used in the tyre industry — Part 1: Pneumatic tyres
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4223-1 and the following 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 https://www.electropedia.org/
3.1 cyclic loading
gradual increase of payload to maximum allowable load with unloading before off-field transport
3.2 basic tyre load
tyre load-carrying capacity indicated by the tyre’s load index at the reference speed indicated by the tyre’s speed symbol
Note 1 to entry: When used as dual tyres, the load per tyre shall be reduced to 88 % of the single tyre load.
3.3 high and sustained torque
condition that occurs when high continuous tractive effort is applied to the drawbar or hitch
Note 1 to entry: Vehicles equipped with injectors or any other ground engaging attachment (e.g. ploughing) or dragging objects are considered to be operating in a high and sustained torque mode. Vehicles pulling carts or trailers are also considered to be operating in a high torque mode when operating on slopes greater than 11°
(20 %) lateral slope.
4 Tyre marking
4.1 General
The tyre marking shall consist of the designation of the dimensional and constructional characteristics (tyre size designation), the service description (load index and speed symbol) and any other additional markings (see example in Figure 1).
4.2 Supplementary service description
Tyres may also be marked with an additional service description, indicated within a circle, to identify a special type of service (load rating and speed category) for which the tyre size is also allowed in addition to the applicable load variation with speed (see example in Figure 2).