ISO metric precision hexagon bolts screws and nuts Specification
BritishStandard Committeesresponsibleforthis
The preparation of this British Standard was entrusted to Technical CommitteeFME/9Bolts nuts and accessories(QA and hose clamps) uponwhich the following bodies were represented:
British Constructional Steelwork Association Ltd Confederation of British ForgersElectricity AssociationSociety of Motor Manufacturers and Traders LimitedUK Steel Association
Amendments issued since publication
First published December 1963Second edition August 1967 Third edition February 2001
Amd. No Date CommentsCorrigendum No.1 13183 May 2001 Two values in column 7 of Table 5 corrected forM18and M20.Correction of title ofFigure E.12
The following BSI referenoesBritish Standard: relate to the work on thisCommittee reference FME/9Draft for ment 00/711040 DC
ISBN 0 580 33262 4
Contents
Committees responsible Inside front cover PageForeword i1 Scope 12 3 Normative references Finishes 24 General dimensions 25 6 Length of bolts and screws Ends of bolts and screws 27 Screw threads 2 28 Length of thread on bolts and screws 39 10 Chamfering washer facing and countersinking Angularity and eccentricity of bolts screws and nuts 3 411 Strength grade designation system for steel bolts and screws 412 13 Mechanical properties of steel bolts and screws Material and manufacture of steel bolts and screws 4 514 Strength grade designation system for steel nuts 515 16 Material and manufacture of steel nuts Mechanical properties of steel nuts (excluding thin nuts) 6 617 Drilled bolts with split pin holes 618 Inspection and testing Marking and identification (see also Annex E) 619 20 Complete designation for the purpose of an enquiry or order 6 7Annex A (normative) Remended gauge for checking squareness ofthread to face of nut (see clause 9) Annex B (normative) Chemical position of steel nuts (see 15.2) 18 18Annex C (normative) Testing of mechanical properties of steel nutsAnnex D (informative) Association of bolt and screw lengths and diameters (see clauses 16 and 19) 19Annex E (informative) Basis for the derivation of tolerances (see clause 8) 21Annex F (informative) Manufacturers' remended range of sizes 24 30Bibliography 32Figure 2-Hexagon head bolt Figure 1 Depth of decarburization on steel bolts and screws 5Figure 3-Hexagon head screw 7 8Figure 4 - Full bearing head washer face 8Figure 5- Rounded end Figure 6 - Rolled thread end 8Figure 7 - Normal thickness nut 11 8Figure 8-Thin nut Figure 9- Enlarged view of nut countersink 11Figure 10-Slotted nut. Sizes M4 to M39 only (Six slots) 12 14Figure 11 - Castle nut. Sizes M12 to M39 only (Six slots) 14Figure A.1 -Nut squareness gauge Figure 12 - Castle nut. Sizes M42 to M68 only (Eight slots) 14 18Figure C.1 Proof load test for nut 19Figure C.2-Examples of marking of forged nuts 20
PageFigure E.1 - Widths across flats Figure C.3-Examples of marking of bar turned nut 20Figure E.2-Widths across corners 24 24Figure E.4-Shank diameter of full size bolts Figure E.3-Heights of heads 24Figure E.5 - Nominal length 25 25Figure E.6 -Thread lengths Figure E.7-Eecentricity of the head 25Figure E.8-Angularity of the hand 25 26Figure E.9 - Eecentricity between shank and thread 26Figure E.10-Eecentricity of split pin hole Figure E.11 - Widths across flats 26 27Figure E.12 -Widths across corners 27Figure E.13-Thicknesses of nuts Figure E.14 -Dimensions of slots 27Figure E.15-Eccentricity of the hexagon 28 28Figure E.16-Eccentricity of the slotsTable 1 Basis for standard thread lengths Figure E.17-Angularity of the nuts 29 3Table 2-Strength grade designations of steel bolts and screws 4Table 4- Remended bolt and nut binations Table 3Strength grade designations of steel nuts 5Table 5 ISO metric precision hexagon bolts and screws 6 9Table 6-ISO metric precision hexagon nuts and thin nuts Table 7 - ISO metric precision hexagon slotted nuts and castle nuts 13Table 8 - Tolerances on the standard nominal lengths of bolts and screws 15 16Table 9-Mechanical properties of steel nuts 16Table 10- Proof loads for steel nuts (coarse pitch series) Table B.1-Chemical position of steel nuts 17Table C.1 - Strength grade designation marking of nuts 20 18Table D.1 - Preferred standard sizes of ISO metric precision hexagon bolts and screws 21Table D.2 - Standard thread lengths and the shortest lengths designated as bolts related to diameterTable F.1-Hexagon head bolts 23Table F.2-Hexagon head screws 31
Foreword
Thisnewedition of the BritishStandard has been prepared bySub-Committee FME/9/6 General purpose fasteners and accessorieson behalfofTechnicalCommitteeFME/9Boltsnutsandaccessories.ItsupersedesBS3692:967 which is withdrawn. This new edition embodies the text of amendment No.1(AMD 1720) and amendment No. 2 (AMD 8227).
Theneedforboltsscrews andnutscovered bythis BritishStandard hasbeen reviewed andit has been decided in theinterests of safety to deleteBS3692:1967 Tables 10 and 13(mechanical properties for bolts and screws)and to produce a new edition.In this edition BSENISO S98.1 has been referred toasit reflects current thinking and practice of the mechanical properties for suchproducts.This edition cross-refers to tables for mechanical properties of bolts and brings the specification into line with BS EN ISO 898-1.
Annex A and Annex B are normative. Annex C Annex D Annex E andAnnex F are informative.
It has been assumed in the drafting of this British Standard that the executionof its provisions is entrusted to appropriately qualified and experienced people for whose guidance it has been prepared.
A BritishStandard does not purport to include all necesary provisions of acontract. Users of British standards are responsible for their correct application.
Compliance with a British Standard does not of itself confer immunity from legal obligations.
Summary of pages
This document prisesa front cover an nside front cover pagesitoiv pages 1 to 32 an inside back cover and a back cover.
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