scope:

This Standard establishes the basic triangular profile for the MJ thread form; provides a system of designations; lists the standard series of diameter/pitch combinations for diameters from 1.6 to 200 mm; and specifies limiting dimensions and tolerances.

It specifies the characteristics of the MJ metric series of threads having a minimum 0.15011P radius at the root of the external thread, and also having the minor diameter of the external and internal threads increased above the ASME B1.13M thread form to accommodate the external thread root radius.