This part of ISO 128 specifies general principles and basic methods for the application of the simplified representation on mechanical engineering drawings. The provisions of this part of ISO 128 are based on those of ISO 128-20, ISO 128-30, ISO 128-40, ISO 128-50, ISO 129-1 (Technical drawings — Indication of dimensions and tolerances — Part 1: General principles) and ISO 6411 (Technical drawings — Simplified representation of centre holes). NOTE For the simplified representation of individual products, such as fastenings, springs, seals, gear wheels, racks, worms, worm gear-wheels, splint joints and rolling bearings, see the relevant International Standards.