This International Standard specifies, with reference to ISO 230-1, the geometric tests and corresponding tolerances for self-centring, manually-operated chucks for machine tools with more than two jaws. This type of chuck has jaws known as "one-piece hard jaws", the relatively large stroke of which allows quick adaptation to the most varied sizes of workpieces without dismounting. This International Standard deals only with the inspections of rotational accuracy of the chuck, the straightening and the centring of workpieces. It is not applicable to other dynamic quantities, such as measurement of counterbalancing or measurements gripping powers.