1、DEUTSCHE NORM January 2001 Fasteners - Electroplated coatings English version of DIN EN IS0 4042 (IS0 4042 : 1999) DIN EN IS0 4042 - ICs 21.060.01 ; 25.220.40 Verbindungselemente - Galvanische berzge (IS0 4042 : 1999) Supersedes October 1999 edition. European Standard EN IS0 4042 : 1999 has the stat
2、us of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been published in accordance with a decision taken by CEN/TC 185 to adopt, without alteration, International Standard IS0 4042 as a European Standard. The responsible German body involved in its preparat
3、ion was the Normenausschuss Mechanische Verbin- dungselemente (Fasteners Standards Committee), Technical Committee Oberflachenschutz. DIN EN IS0 3269 and DIN EN IS0 15330*) are the standards corresponding to International Standards IS0 3269 and IS0 15330, respectively, referred to in clause 2 of the
4、 EN. Amendments This standard differs from the October 1999 edition in that a printing error in the German version has been corrected. Previous editions DIN IS0 4042: 1992-06; DIN EN IS0 4042: 1999-1 O. National Annex NA Standards referred to (and not included in Normative references, Bibliography a
5、nd Annex ZA) DIN EN IS0 3269 Fasteners - Acceptance inspection (IS0 3269 : 2000) DIN EN IS0 15330 Fasteners - Preloading test for the detection of hydrogen embrittlement - Parallel bearing surface method (ISO/DIS 15330 : 1997)*) *) Currently at draft stage. EN comprises 23 pages. I Q No pari of this
6、 standard may be reproduced without the prior permission of Ref. No. DIN EN IS0 4042 : 2001 -0 DIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany, has the exclusive right of sale for German Standards (DIN-Normen). English price group 13 Sales No. 11 13 05.01 EU
7、ROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN IS0 4042 June 1999 ICs 21.060.10 English version Fasteners - Electroplated coatings (IS0 4042 : 1999) Elments de fixation - Revtements lectrolytiques (IS0 4042 : 1999) Verbindungselemente - Galvanische berzge (IS0 4042 : 1999) This European Standard
8、 was approved by CEN on 1999-05-26. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nati
9、onal stand- ards may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and n
10、otified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Sw
11、itzerland, and the United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1999. CEN - All rights of exploitation in any form and by any means reserved worldwide for CEN nation
12、al members. Ref. No. EN IS0 4042 : 1999 E Page 2 EN IS0 4042 : 1999 Foreword International Standard IS0 4042 : 1999 which was prepared by ISO/TC 2 Fasteners of the International Organization for Standardization, has been adopted by Technical Committee CEN/TC 185 Threaded and non-threaded mechanical
13、fasteners and acces- sories, the Secretariat of which is held by DIN, as a European Standard. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, and conflicting national standards withdrawn, by December 1999 at the l
14、atest. In accordance with the CENKENELEC Internal Regulations, the national standards organizations of the follow- ing countries are bound to implement this European Standard: Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Ne
15、therlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. Fasteners - Electroplated coatings, Endorsement notice The text of the International Standard IS0 4042 : 1999 was approved by CEN as a European Standard without any modification. NOTE: Normative references to internatio
16、nal publications are listed in Annex ZA (normative). Contents Page 1 scope 3 2 Normative references 3 3 Terms and definitions 4 . 4 Dimensional requirements and gauging . 4.1 Dimensional requirements before electroplating 4.2 Dimensional requirements after electroplating . 5 Mher coating requirement
17、s 6 Hydrogen embrittlement relief 7 Corrosion protection . 8 Applicability to fasteners that cut or form their own mating threads 9 Specification of coating thickness . 10 Measurement of coating thickness . 10.1 Local thickness 7 10.2 Batch average thickness g 10.3 Agreement on test method g 11 Samp
18、ling for thickness tests g 9 13 Designation 9 Annex A (informative) Hydrogen ernbrittlement relief . 1 o Annex B (informative) Salt spray corrosion protection performance of metallic coatings . 12 12 Ordering requirements for electroplating . Annex C (informative) Guidance on procedures that may be
19、adopted to accommodate thick coatings . 14 Annex D (normative) Determination of batch average thickness 15 Annex E (normative) Designation code, system A, for electroplated coatings on threaded parts . 18 Annex F (informative) Examples for coating designation . 20 Annex G (informative) Surface areas
20、 of bolts, screws and nuts 21 Bibliography 23 Page 3 EN IS0 4042 : 1999 1 Scope This Internation: Standard specifies dimensional requirements for electropla Isteners of steel or copper alloy. It specifies coating thicknesses and gives recommendations for hydrogen embrittlement relief for fasteners w
21、ith high tensile strength or hardness and for surface-hardened fasteners. This International Standard primarily concerns the electroplating of threaded fasteners, but it may also be applied to other threaded parts. For the applicability to screws that cut or form their own mating threads, see clause
22、 8. The specifications given in this International Standard may also be applied to non-threaded parts such as washers and pins. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For
23、 dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For
24、 undated references, the latest edition of the normative document referred to applies. Members of IS0 and IEC maintain registers of currently valid Intemational Standards. IS0 965-1 :1999, IS0 general purpose metric screw threads - Tolerances - Part I: Principles and basic data. IS0 965-2:1999, IS0
25、general purpose metric screw threads - Tolerances - Part 2: Limits of sizes for general purpose bolt and nut threads - Medium quality. IS0 965-3: 1999, IS0 general purpose metric screw threads - Tolerances - Part 3: Deviations for constructional threads. IS0 1456:1988, Metallic coatings - Electrodep
26、osited coatings of nickel plus chromium and of copper plus nickel plus chromium. IS0 1458:1988, Metallic coating - Electrodeposited coatings of nickel. IS0 15021 996, IC0 general purpose metric screw threads - Gauges and gauging. IS0 2064:1996, Metallic and other non-organic coatings - Definitions a
27、nd conventions concerning the measurement of thickness. IS0 2081 :1986, Metallic coatings - Electroplated coatings of zinc on iron or steel. IS0 20821 986, Metallic coatings - Electroplated coatings of cadmium on iron or steel. Page 4 EN IS0 4042 : 1999 IS0 3269:- ), Fasteners - Acceptance inspectio
28、n. IS0 4520: 1981 , Chromate conversion coatings on electroplated zinc and cadmium coatings. IS0 9227:1990, Corrosion tests in artificial atmospheres - Salt spray tests. IS0 9587:2), Metallic and other inorganic coatings - Pre-treatments of iron or steel for reducing the rick of hydrogen embrittleme
29、nt. IS0 15330:2), Fasteners - Preloading test for the detection of hydrogen embrittlement - Parallel bearing surface method. 3 Terms and definitions For the purposes of this Intemational Standard, the definitions given in IS0 2064 (in particular, the definitions of significant surface, measuring are
30、a, local thickness and minimum local thickness) and IS0 3269 together with the following, apply. 3.1 batch quantity of identical fasteners from the same manufacturing lot processed together at one time 3.2 production run those batches of parts processed continuously without any changes in coating te
31、chniques or constituents 3.3 batch average thickness calculated average thickness of a coating if it was uniformly distributed over the surface of the parts of the batch 3.4 baking process of heating parts for a definite time at a given temperature in order to minimize the risk of hydrogen embrittle
32、ment 3.5 baking duration time at which the parts are held at the specified temperature which they shall have completely reached To be published. (Revision of IS0 3269:1988) 2, To be published. Page 5 EN IS0 4042 : 1999 4 Dimensional requirements and gauging 4.1 Dimensional requirements before electr
33、oplating Before coating, parts shall comply with the relevant International Standards if applicable or other standards as specified, except where threads or other features are specifically manufactured to allow, for functional reasons, the application of thicker coatings than are possible on normal
34、threads. Coating thicknesses which can be applied on IC0 metric threads in accordance with IS0 965-1, IS0 965-2 and IS0 965-3 depend on the fundamental deviation available, which itself depends on the screw thread and the following tolerance positions: - g, f, e for external threads; - The tolerance
35、 positions apply prior to application of the electroplated coating. 4.2 Dimensional requirements after electroplating G for intemal threads or H if required. After coating, IS0 metric screw threads shall be gauged in accordance with IS0 1502 with a GO gauge of tolerance position h for extemal thread
36、s and H for intemal threads. Other product dimensions apply only before coating. NOTE of internal drives; in these cases an agreement should be made between the supplier and the purchaser. The applicability of the recommended coatings to IS0 metric threads is limited by the fundamental deviation of
37、the threads concerned and hence, by the pitch and tolerance positions. The coating shall not cause the zero line (basic size) to be exceeded in the case of external threads, nor shall it fall below this line in the case of internal threads. This means that for an internal thread of tolerance positio
38、n H, a measurable coating thickness can only be applied to the threads if the tolerance zone is not taken up to the zero line (basic size). Care should be exercised where relatively thick coatings may affect dimensions with small tolerances as in the case 5 Other coating requirements The electroplat
39、ed coating shall comply with the provisions of the relevant International Standards (IS0 1456, IS0 1458, IS0 2081, IS0 2082) for the coating concerned in respect of appearance, adhesion, ductility, corrosion resistance. etc. 6 Hydrogen embrittlement relief In cases of parts - with high tensile stren
40、gth or hardness or which have been surface hardened, - which have absorbed hydrogen and - are under tensile stress there is the risk of failure due to hydrogen embrittlement. When the core or surface hardness is above 320 HV, process investigation shall be conducted using a test to detect hydrogen e
41、mbrittlement, for example the “Parallel bearing surface method“ in accordance with IS0 15330, to be sure that the process with regard to embrittlement is under control. If embrittlement is discovered, modification of the manufacturing process will be necessary, such as the inclusion of a baking proc
42、ess (see informative annex A for more information). Page 6 EN IS0 4042 : 1999 For fasteners of hardness in excess of 365HV, a written agreement should exist between the customer and manufacturer to define how to manage the risk. If written agreement does not exist, the manufacturer shall process the
43、 parts in accordance with his recommended practices to reduce the risk of hydrogen embrifflement. Complete elimination of hydrogen embrittlement cannot be assured. If a reduced probability of encountering hydrogen embrittlement is desired, alternative procedures should be evaluated. NOTE Investigati
44、ons are proceeding to develop methods for the reduction of hydrogen embrittlement. 7 Corrosion protection The corrosion protection of an electroplated coating depends to a considerable extent on its thickness. In addition to greater coating thickness, a chromate conversion treatment can be specified
45、 for increased corrosion protection on zinc and cadmium coatings. Contact with other metals and materials, the frequency and duration of wetting and service temperatures may influence the protective performance of coatings and expert advice is essential when uncertainties of choice arise. Coatings o
46、f Zn and Cd applied to ferrous substrates are less electropositive than the steel base metal and consequently provide cathodic protection. In contrast, Ni and Cr coatings are more electropositive than the steel base metal and may intensify part corrosion where the coating is damaged or pitted. Cadmi
47、um coatings are dealt with in IS0 2082. Zinc coatings are dealt with in IS0 2081. Nickel coatings are dealt with in IS0 1458. Nickel + chromium and copper + nickel + chromium coatings are dealt with in IS0 1456. Chromate conversion treatments are dealt with in IS0 4520. NOTE Information on salt spra
48、y corrosion protection performance of metallic coatings is given in informative annex B. 8 Applicability to fasteners that cut or form their own mating threads All recommended coatings may be applied to screws that cut or form their own mating threads such as wood screws, self tapping screws, self d
49、rilling screws and thread forming screws. The maximum value for batch average thickness given in Table 1 may be ignored unless otherwise specified. 9 Specification of coating thickness The local and batch average thicknesses corresponding to the nominal coating thicknesses recommended in the relevant International Standards for electroplating are given in Table 1. In order to reduce the risk of interference on assembly of threads with electroplated coatings, the coating thickness shall not exceed one-quarter of the fundamental deviation of the thread. These values are specif
