This part of ISO 7 specifies a process using limit gauges, for the validation of taper internal and external threads

and parallel internal threads on piping systems components and other products, the dimensions and tolerances of

which are detailed in ISO 7-1.

The gauging system described may not be suitable, without special precautions, for gauging of threads on injection

moulded plastic workpieces.

This part of ISO 7 does not cover completely all the requirements necessary for full control of thread quality and

dimensions. Additional control of tools and equipment and visual inspection during production are required to

ensure complete compliance with ISO 7-1, for example the length of useful thread on internally threaded

workpieces should be checked by direct measurement.

Annex A gives a summary of the gauges included in this part of ISO 7, together with details of the thread elements

controlled by each gauge and gauge identification numbers.

In the event of a dispute over compliance with the requirements of ISO 7-1, the gauges in this part of ISO 7 are to

be considered as decisive for the thread elements which they control on the workpiece.