This part of ISO 9988 specifies the methods of preparation of test specimens and the test methods to be used in determining the properties of polyoxymethylene moulding and extrusion materials. Requirements for handling test material and for conditioning both the test material before moulding and the specimens before testing are given. Procedures and conditions are described for the preparation of test specimens, and procedures are given for measuring properties of the materials from which these specimens are made. Properties and test methods which are suitable and necessary to characterize polyoxymethylene moulding and extrusion materials are listed. The properties have been selected from the general test methods in ISO 10350-1:1998. Other test methods in wide use for, or of particular significance to, these moulding and extrusion materials are also included in this part of ISO 9988 as designatory properties specified in ISO 9988-1: melt flow rate and tensile modulus. In order to obtain reproducible and comparable test results, it is necessary to use the methods of specimen preparation and conditioning. The specimen dimensions and the test procedures are specified herein. Values determined will not necessarily be identical to those obtained using specimens of different dimensions or prepared using different procedures.