1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ICS 21.060.10 ISBN 0-626-15639-4 SANS 1700-5-13:1996 Edition 1 and nat. amdt 1 ISO 6157-3:1988 Edition 1 Any reference to SABS 1700-5-13 is deemed to be
4、a reference to this standard (Government Notice No. 1373 of 8 November 2002) SOUTH AFRICAN NATIONAL STANDARD Fasteners Part 5: General requirements and mechanical properties Section 13: Surface discontinuities Bolts, screws and studs for special requirements This national standard is the identical i
5、mplementation of ISO 6157-3:1988 and is adopted with the permission of the International Organization for Standardization. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za S
6、tandards South Africa SANS 1700-5-13:1996 Edition 1 and nat. amdt 1 ISO 6157-3:1988 Edition 1 Table of changes Change No. Date Scope Nat. amdt 1 2004 Amended to change the designation of SABS standards to SANS standards with no technical changes. Abstract Establishes limits for various types of surf
7、ace discontinuities on bolts, screws and studs for special requirements. Keywords bolts, fasteners, mechanical properties of materials, specifications, studs (fasteners), surface defects, surface discontinuities. National foreword This South African standard was approved by National Committee StanSA
8、 TC 5120.01, Screw threads and fasteners, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This edition is technically identical to SABS 1700-5-13:1996. ISO6157-3:1988 (E) 3.1.5 Forging Cracks in socket head screws Cause Appearance Cracks
9、in the peripher-y, in the top surface and on the indented Portion (hexagon socket) may occur on the inner and outer faces due to tut-off of wire section, shear and compressive stress during forging operations and countersinking of head. Permissible 1 Permissible - does not extend more than half the
10、distance between the periphery of the head and the socket Not permissible - connects socket and edge of head Permissible 7 Permissible - Not permissible - potential intersecting discontinuities /4- Permissible i Not permissible Permissibled Permissible _ Not permissible - connects socket and edge of
11、 head LNot permissible - potential intersecting discontinuities l- Permissible I, 5 ISO 6157-3 : 1988 (E) Appearance kontinued) Permissib Ile depths : hl 0,03d$): 0,13 mm max. r Permissible Not permissible - potential intersecting discontinuities Permissible - not in area of key engagement (bottom o
12、f socket) h 1 -Not permissible - transverse discontinuities in the fillet area h2 G 0,06dk: 1,6 mm max. 0,3 t2 +- No Cracks permissible 1 I in this area Permissible 1) dk = head diameter 2) t= key engagement socket depth D K-Not permissible - bottom of socket or within 0,3t of bottom of socket ISO 6
13、157-3 : 1988 (EI Limits Cracks extending from the socket to the outer face and Cracks with a traverse indicating a potential to intersect are not permissible. Cracks within 0,3t of the bottom of the socket are not permissible. Cracks located elsewhere in the socket are permissible, provided that the
14、y do not exceed a length of 0,25t and a depth of 0,03 - at the loaded flank of screw thread below the pitch diameter, even if they Start beyond the pitch dia- meter. The following laps are permissible: - laps in the crest of the threads of 0,25 Hl max.; - crest of the threads not entirely rolled out
15、, maximum half a turn on one thread; - laps below the pitch diameter, if they run on the non-loaded flank towards the major diameter and not deeper than 0,25 Hl and not longer than half a turn on one thread. 3.7 Damages Damages are indentations of any surface of a bolt or screw. I Cause I Damages, f
16、or example dents, scrapes, nicks and gouges, are produced by externai action during manufacture and handling of bolts and screws, for example during loading. 1 Appearance 1 No precise geometrical shape, location or direction, identifiable as external action. Limits Damages as described above shall n
17、ot Cause rejection unless it tan be shown that they impair function or usability. Dents, scrapes, nicks and gouges on the first three threads shall be such that they allow the screwing on of a go-ring gauge with torque values of 0,001 d3 max., in newton metres. A specific agreement on packaging, for
18、 example, may be necessary in Order to avoid darnage during transport. 10 ISO 6157-3 : 1988 (E) 4 Inspection and evaluation procedure For the acceptance inspection procedure, see ISO 3269. Sur- face coatings shall be removed before examination id identifi- cation of the surface discontinuities is im
19、paired. NOTE - The 1984 edition of ISO 3269 gives no specifications on sampling Plans for surface discontinuities of fasteners. Until this has been completed, the applicable sampling plan is given in the annex. 4.1 Principles The manufacturer is entitled to use any inspection procedures but due care
20、 shall be taken to ensure that products conform to this part of ISO 6157. The purchaser may use the inspection procedure specified in this clause at his acceptance inspection in Order to decide whether a lot of fasteners may be accepted or rejected. This procedure shall also be applied when conforma
21、nce to specifi- cation is disputed, unless some other acceptance procedure has been agreed between the manufacturer and the purchaser at the time of ordering the fasteners. 4.2 Non-destructive testing A random Sample shall be taken from the lot in accordance with table 2 in the annex and subjected t
22、o either visual tests or other suitable tests, e.g. magnetic techniques or eddy current. If no defective product is found the lot shall be accepted (sec also 4.4). If defective products are found these shall form the lot size for the procedures given in 4.3. 4.3 Destructive testing 16 defective prod
23、ucts are detected by the procedures given in 4.2, then a secondary Sample shall be taken from the defective products, in accordance with table 3 in the annex, consisting of the products indicating the most serious defects and sectioned at 90O through the discontinuity where the greatest depth is exp
24、ected. 4.4 Evaluation If on visual inspection any product is found with quench Cracks in any location, or folds at interior corners or below the bearing surface, except “clever leaf” folds in non-circular shoulder fasteners, the lot shall be subject to rejection. If on the destructive test any produ
25、ct is found with forging Cracks, bursts, seams and laps, voids, tool marks or damages which exceed the allowable limits as specified for the applicable type of discontinuity, the lot shall be subject to rejection. 12 ISO 6157-3 : 1988 (EI Annex Sampling plan for surface discontinuities (This annex f
26、orms an integral part of this Standard.) Sampling for surface discontinuities shall be carried out using the Sample sizes given in table 2 and using the principles and procedures given in clause 4. Table 2 - Sample sizes for visual and non-destructive testing Lot sizel) Sample size N n N 1200 20 1 2
27、01 N 10 000 32 10 001 N 35000 50 35001 N 150 000 80 1) Lot size is the number of products of the same type, size and property class submitted for inspection at one time. NOTE - The Sample sizes are based on special inspection level S-4 specified in ISO 2859. Table 3 - Secondary Sample sizes for destructive testing Number of defective products in the Sample N Na 8 2 9Na15 3 16 N a 25 5 26 N 50 8 51 a N80 13 Secondary Sample size n NOTE - The secondary Sample sizes are based on general inspection level II specified in ISO 2859. 13
