BS ISO 965‑3:2021 pdf download – ISO general purpose metric screw threads — Tolerances Part 3: Limit deviations for screw threads.
1 Scope This document specifies limit deviations for pitch and crest diameters for ISO general purpose metric screw threads (M) conforming to ISO 261 having basic profile in accordance with ISO 68-1. The limit deviations specified are derived from the fundamental deviations and tolerances specified in ISO 965-1. This document is applicable to ISO general purpose metric screw threads with the recommended tolerance classes. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5408, Screw threads — Vocabulary 3? Terms? and? definitions For the purposes of this part of document, the terms and definitions given in ISO 5408 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https:// www .org/ obp — IEC Electropedia: available at https:// www .electropedia .org/ 4 Limit deviations Limit deviations are given in Table 1. For internal threads as well as external threads, the actual root contour shall not in any point transgress the basic profile and fundamental deviation. For coated threads, the tolerances apply to the parts before coating, unless otherwise stated. After coating the actual thread profile shall not in any point transgress the maximum material limits for position H or h respectively. NOTE These provisions are intended for thin coatings, for example those obtained by electroplating.