AS 4397-1996

1 - AS 4397-1996 ELECTROPLATED COATINGS OF ZINC ON STEEL FASTENERS WITH IMPERIAL THREADS
4 - PREFACE
5 - CONTENTS
6 - FOREWORD
8 - 1 SCOPE
8 - 2 REFERENCED DOCUMENTS
9 - 3 DEFINITIONS
9 - 3.1 Batch average thickness
9 - 3.2 Inspection batch
9 - 3.3 Local thickness
9 - 3.4 Representative sample (for plating thickness)
9 - 4 DIMENSIONAL REQUIREMENTS BEFORE PLATING
9 - 5 COATING REQUIREMENTS
9 - 5.1 General
9 - 5.2 Coating thickness
9 - 5.2.1 Batch average thickness
9 - 5.2.2 Local thickness
10 - 5.3 Gauging after coating
10 - 5.3.1 General
10 - 5.3.2 Acceptability
10 - 6 APPLICABILITY OF COATING TO STANDARD THREADS
11 - 7 APPLICABILITY OF COATING TO MODIFIED THREADS
11 - 7.1 General
11 - 7.2 External threads
11 - 7.3 Internal threads
12 - 8 HEAT TREATMENT OF STEEL FOR RELIEF OF STRESS AND HYDROGEN EMBRITTLEMENT
12 - 8.1 Heat treatment before plating
12 - 8.2 Heat treatment after plating
12 - 9 CHROMATE CONVERSION COATINGS
12 - 9.1 General
12 - 9.2 Types
13 - APPENDIX A - PURCHASING GUIDELINES
13 - A1 GENERAL
13 - A2 INFORMATION TO BE SUPPLIED BY THE PURCHASER
14 - APPENDIX B - RECOMMENDED SAMPLING PLAN FOR THE INSPECTION OF COATINGS ON THREADED ITEMS
14 - B1 GENERAL
14 - B2 SAMPLING PLAN
14 - B3 ACCEPTANCE AND REJECTION
14 - B4 RESUBMITTED BATCHES
15 - APPENDIX C - NOTES ON SURFACE AREAS OF IMPERIAL SCREWS, BOLTS AND NUTS
15 - C1 THICKNESS DETERMINATION
15 - C2 AREA TABLES
15 - C3 CALCULATION OF SURFACE AREAS OF SCREWS AND BOLTS
16 - C4 NUTS
23 - APPENDIX D - SPECIAL FACTORS FOR THE ELECTROPLATING OF SCREW THREADS
23 - D1 THICKNESS SPECIFICATION
23 - D2 THICKNESS DETERMINATION
25 - APPENDIX E - EXAMPLES OF CALCULATIONS OF PLATING THICKNESSES
25 - E1 BASIC EQUATION
25 - E2 EXAMPLES
28 - APPENDIX G - EFFECT OF MANUFACTURING TOLERANCES ON PLATING THICKNESS CALCULATIONS FOR IMPERIAL THREADS
28 - G1 SCOPE
28 - G2 10-32 UNF, 1 IN LENGTH OF THREAD
28 - G3 1/2 IN UNC, 1 IN LENGTH OF THREAD
30 - APPENDIX H - EXAMPLE OF CALCULATION OF EXTERNAL THREAD DIMENSIONS TO ACCOMMODATE A THICKER COATING
31 - APPENDIX I - HYDROGEN EMBRITTLEMENT RELIEF AFTER ELECTROPLATING

Specifies requirements, including coating thickness, for electroplated coatings of zinc on threaded steel fasteners having inch series threads. It includes a method for the calculation of the degree of thread modification to accommodate thicker coatings when additional protection against corrosion is required. Appendices give details of surface areas for the various types of screws, bolts and nuts; recommended sampling procedures; examples of effect of manufacturing tolerances on plating thickness calculations; and heat treatment procedures.

This Standard sets out requirements for electroplated coatings of zinc, applied either by barrel plating or other techniques, on fasteners with imperial threads (the UNC, UNF and Whitworth series).The Standard requires that coated threads be subject to 'GO' gauge acceptance criteria. It includes a method for the calculation of the degree of thread modification to accommodate thicker coatings.NOTES:1 Advice and recommendations on information to be supplied by the purchaser at the time of inquiry and order are contained in the purchasing guidelines set out in Appendix A.2 This Standard may apply to threaded components other than fasteners, whether barrel or individually processed, subject to agreement between purchaser and supplier.3 A recommended sampling plan for electroplated zinc fasteners is contained in Appendix B.

First published as Part 2 of AS K132-1963 (endorsement of BS 3382-1961 with amendment) AS K132.7 first published 1972.
Second edition of AS K132.2-1973.
AS K132.2-1973 and AS K132.7-1972 revised, amalgamated and redesignated AS 4397-1996.