This standard establishes the basic triangular profile for the MJB thread form, the design profiles, standard pitches, tolerance classes, formulae for tolerances and dimensions, tolerance tables, and a system of designations. Because of the specialized application for buttress threads, no preferred diameter-pitch series have been established for this standard and each application will require use of the thread formulae for dimensions and related tolerances given herein for deriving the thread dimensional requirements.

Purpose:

This standard specifies the characteristics of the MJB metric series of buttress screw threads based on 7°/45° form, with width of truncation same as MJ screw thread profile, and with a controlled radiused root in the external thread.