Data Book & Engineering Design Guides
Most of these Tyre and Rim Standards have two separate documents :-
International Tyre & Rim Standards
Tyre Standards have been in existence since 1903 . These Tyre and Rim Standards came into being because each Tyre required its own special rim and there caused problems with interchangeability between other tyre brands . Four Tyre and three Rim manufactures set up the Standards and then started monitoring conformity. Rims meeting these standards were then given an Approval Stamping . This practice was discontinued in 1973. It had become the norm for manufacturers to just automatically comply with these standards for convenience to the industry .
Today there are a number of Tyre and Rim Standards in the industry :-
T&RA - Tyre and Rim Association ( Originally only USA ) .
ETRTO - European Tyre and Rim Technical Organisation .
JATMA - Japanese Automobile Tyre Manufacturers Association .
SANS 1550-3:2006 - South African National Standard ( Formerly TREDCO ).
Some of these Standards are guidelines , whilst others are mandatory documents . The important issue is for Global Trade it is important that there is conformity between all these Standards . By enlarge this holds true except for some uncommon sizes that are unique to one Standard.