What are the tolerances on the length and the width of belts?

There is an international standard, EN ISO 15147, for conveyor belts. No such standard exists for power transmission belts.Habasit affiliated companies operate according to their own individual standards, which generally define tighter tolerances than EN ISO 15147.
Customer-specific tolerances may be specified in the order, though there are limits due to the nature of synthetic materials and processes involved.