BS ISO 3353-1:2020 pdf free.Aerospace一Lead and runout threads.Rolled external threads.
BS ISO 3353-1 1 Scope This document specifies the lead and runout requirements for rolled external threads for aerospace construction, and the inspection method to be used in case of dispute. It is applicable whenever it is referenced in a definition document. 2 Normative references There are no normative references in this document. 3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses:
ISO Online browsing platform: available at https://www.iso.org/obp 一IEC Electropedia: available at http://www.electropedia.org/3.1 lead thread portion of the incomplete thread that is fully formed at the root but not at the crest which occurs at the beginning end of either external or internal threads 3.2 runout thread part of the screw thread in which is located the thread incompletely formed during rolling, between the completely formed threads and the part which has not been rolled 3.3 completely formed thread thread, the profile of which (ABC) is located, over an axial distance of 1P, within the limits specified in the definition document for the thread Note 1 to entry: See Figure 1.6.1 General The method is left to the discretion of the manufacturer, provided that it ensures conformity with the requirements given in Clause 5.In case of dispute, the method by optical projection, defined hereafter, shall be used. See
comments in Annex A. 6.2 Use of the charts The charts shall be used in conjunction with a profile projection comparator having a magnifying power equal to or greater than x20. 6.3 Procedure 6.3.1 For lead threads The inspection shall be carried out using a chart drawn in accordance with Figure 10.BS ISO 3353-1 pdf downlaod.