This International Standard recommends the adjustment values which are valid for the most commonly used belts and for conveyors with a maximum length not greater than 300 m, fitted solely with fabric carcass belts. Owing to the wide variety of belt types, and to the number of determining factors in choosing the adjustment, it is not possible to propose general numerical values applicable to all cases. For belts with a fabric carcass whose length exceeds 300 m and belts with a metal carcass of any length, the manufacturer should justify the chosen adjustment.