1、August 2011 Translation by DIN-Sprachendienst.English price group 8No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS
2、21.060.10!$sl0“1807313www.din.deDDIN EN ISO 2702Heat-treated steel tapping screws Mechanical properties (ISO 2702:2011)English translation of DIN EN ISO 2702:2011-08Wrmebehandelte Blechschrauben aus Stahl Mechanische Eigenschaften (ISO 2702:2011)Englische bersetzung von DIN EN ISO 2702:2011-08Vis tl
3、e en acier trait thermiquement Caractristiques mcaniques (ISO 2702:2011)Traduction anglaise de DIN EN ISO 2702:2011-08SupersedesDIN EN ISO 2702:1994-10www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1207.11 DIN EN ISO 2702:2011-08
4、2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee ISO/TC 2 “Fasteners” in collaboration with Technical Committee CEN/TC 185 “Fasteners” (both secretariats are held by DIN, Germany). The responsible German body involved in its preparatio
5、n was the Normenausschuss Mechanische Verbin-dungselemente (Fasteners Standards Committee), Working Committee NA 067-00-05 AA Kleinschrauben und gewindeformende Schrauben. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 898-7 DIN EN 208
6、98-7 ISO 1478 DIN EN ISO 1478 ISO 6507-1 DIN EN ISO 6507-1 Amendments This standard differs from DIN EN ISO 2702:1994-10 as follows: a) the scope has been extended to include ST 9,5; b) in Subclause 4.1.3, the maximum core hardness has been reduced from 390 HV to 370 HV; c) in Subclause 6.2.2, a ref
7、erence to ISO 898-7 has been included regarding the torque-measuring device. Previous editions DIN 267-12: 1971-11 DIN EN ISO 2702: 1994-10 National Annex NA (informative) Bibliography DIN EN 20898-7, Mechanical properties of fasteners Part 7: Torsional test and minimum torques for bolts and screws
8、with nominal diameters 1 mm to 10 mm DIN EN ISO 1478, Tapping screw thread DIN EN ISO 6507-1, Metallic materials Vickers hardness test Part 1: Test method EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 2702 May 2011 ICS 21.060.10 Supersedes EN ISO 2702:1994English Version Heat-treated stee
9、l tapping screws - Mechanical properties (ISO 2702:2011) Vis tle en acier trait thermiquement - Caractristiques mcaniques (ISO 2702:2011) Wrmebehandelte Blechschrauben aus Stahl - Mechanische Eigenschaften (ISO 2702:2011) This European Standard was approved by CEN on 28 April 2011. CEN members are b
10、ound to comply with the CEN/CENELEC 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 national standards may be obtained on application to the
11、 CEN-CENELEC Management Centre or to any CEN member. This European Standard exists 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 notified to the CEN-CENELEC Management Centr
12、e has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norwa
13、y, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form a
14、nd by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 2702:2011: EContents DIN EN ISO 2702:2011-08 EN ISO 2702:2011 (E) 2 Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Materials .5 4 Requirements.5 4.1 Metallurgical requirements .5 4.1.1 Surface hardness.
15、5 4.1.2 Case depth5 4.1.3 Core hardness6 4.1.4 Microstructure6 4.2 Mechanical requirements6 4.2.1 Thread-forming capability.6 4.2.2 Torsional strength .6 5 Acceptance.6 6 Test methods6 6.1 Test methods for the metallurgical requirements6 6.1.1 Surface hardness test .6 6.1.2 Case depth Microscopic te
16、st .6 6.1.3 Core hardness test 6 6.1.4 Microstructure test 7 6.2 Test methods for the mechanical requirements.7 6.2.1 Drive test.7 6.2.2 Torsional strength test8 Bibliography 10 Foreword collaboration with Technical Committee CEN/TC 185 “Fasteners” the secretariat of which is held by DIN. This Europ
17、ean Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2011, and conflicting national standards shall be withdrawn at the latest by November 2011. Attention is drawn to the possibility that some of the el
18、ements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 2702:1994. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the follo
19、wing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slova
20、kia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 2702:2011 has been approved by CEN as a EN ISO 2702:2011 without any modification. DIN EN ISO 2702:2011-08 EN ISO 2702:2011 (E) 3 This document (EN ISO 2702:2011) has been prepared by Technical Commi
21、ttee ISO/TC 2 “Fasteners” in Introduction The primary objective of this International Standard is to ensure that tapping screws form mating threads in materials into which they are normally driven without deforming their own thread and without breaking during assembly or service. DIN EN ISO 2702:201
22、1-08 EN ISO 2702:2011 (E) 4 1 Scope This International Standard specifies the characteristics of heat-treated steel tapping screws, with tapping screw thread from ST2,2 to ST9,5 inclusive according to ISO 1478, together with the corresponding test methods. 2 Normative references The following refere
23、nced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 898-7:1992, Mechanical properties of fasteners Part 7: Torsional
24、test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm ISO 6507-1, Metallic materials Vickers hardness test Part 1: Test method 3 Materials Tapping screws shall be made from cold heading, case hardening quality steel. 4 Requirements 4.1 Metallurgical requirements 4.1.1 Su
25、rface hardness The minimum surface hardness after heat treatment shall be 450 HV 0,3 (see ISO 6507-1). 4.1.2 Case depth The case depth shall conform to the values given in Table 1. Table 1 Case depth Dimensions in millimetres Thread Case depth min. max. ST2,2, ST2,6 0,04 0,10 ST2,9, ST3,3, ST3,5 0,0
26、5 0,18ST3,9, ST4,2, ST4,8, ST5,5 0,10 0,23 ST6,3, ST8, ST9,5 0,15 0,28DIN EN ISO 2702:2011-08 EN ISO 2702:2011 (E) 5 4.1.3 Core hardness The core hardness after heat treatment shall be 270 HV 5 to 370 HV 5 for threads ST3,9, and 270 HV 10 to 370 HV 10 for threads ST4,2. 4.1.4 Microstructure The micr
27、ostructure shall show no band of free ferrite between the case and core. 4.2 Mechanical requirements 4.2.1 Thread-forming capability Tapping screws shall form a mating thread without deforming their own thread when driven into a test plate, in accordance with 6.2.1. 4.2.2 Torsional strength Tapping
28、screws shall have a torsional strength such that the torque necessary to cause failure, when tested in accordance with 6.2.2, shall equal or exceed the minimum torque values given in Table 3 for the applicable screw threads. 5 Acceptance For routine acceptance tests, the drive test, torsional test a
29、nd core hardness test may be used, but for referee purposes all requirements specified in this International Standard shall be satisfied. 6 Test methods 6.1 Test methods for the metallurgical requirements 6.1.1 Surface hardness test The Vickers hardness test shall be carried out in accordance with I
30、SO 6507-1. The impression of the pyramid shall be made on a flat face, preferably on the screw head. 6.1.2 Case depth Microscopic test Case depth shall be measured at the thread flank mid-point between crest and root or, in the case of smaller tapping screws up to ST3,9, in the root of the thread. F
31、or referee purposes, a micro hardness plot shall be made using a Vickers indenter and a 300 g load on the thread profile of a properly prepared metallographic specimen. The case depth shall be the point at which the hardness recorded is 30 HV above the actual core hardness. 6.1.3 Core hardness test
32、The Vickers core hardness test shall be carried out in accordance with ISO 6507-1 at the mid-radius of a transverse section through the screw taken at a distance sufficiently behind the point of the screw to be through the full minor diameter. DIN EN ISO 2702:2011-08 EN ISO 2702:2011 (E) 6 6.1.4 Mic
33、rostructure test The microstructure test shall be carried out by metallographic examination. 6.2 Test methods for the mechanical requirements 6.2.1 Drive test The sample screw (coated or uncoated, as received) shall be driven into a test plate until a thread of full diameter is completely through th
34、e test plate. The test plate shall be made from low carbon steel with a carbon content not exceeding 0,23 %. The hardness of the plate shall be 130 HV to 170 HV measured in accordance with ISO 6507-1. The thickness of the plate shall conform to the values given in Table 2. The test hole shall be dri
35、lled, or punched and redrilled, or reamed to the hole diameter specified in Table 2 for the size of screw being tested. Table 2 Standard test plate thickness and hole diameter for drive test Dimensions in millimetres Thread Plate thickness Hole diameter min. max. min. max. ST2,2 1,17 1,30 1,905 1,95
36、5 ST2,6 1,17 1,30 2,185 2,235 ST2,9 1,17 1,30 2,415 2,465 ST3,3 1,17 1,30 2,68 2,73 ST3,5 1,85 2,06 2,92 2,97 ST3,9 1,85 2,06 3,24 3,29 ST4,2 1,85 2,06 3,43 3,48 ST4,8 3,10 3,23 4,015 4,065 ST5,5 3,10 3,23 4,735 4,785 ST6,3 4,67 5,05 5,475 5,525 ST8 4,67 5,05 6,885 6,935 ST9,5 4,67 5,05 8,270 8,330
37、In cases where screws are plated subsequent to delivery to the purchaser (or where plating of screws is otherwise under the control of the purchaser), the producer is not responsible for failure due to plating. In such cases, the screw manufacturer can only be held responsible if it is proved that t
38、he failure is not due to any post-treatment. Screws from which the plating has been stripped off cannot be considered as samples. DIN EN ISO 2702:2011-08 EN ISO 2702:2011 (E) 7 Key 1 split threaded die or threaded insert 2 threaded insert with a blind hole 3 split threaded die Figure 1 Torsional tes
39、t apparatus 6.2.2 Torsional strength test The shank of the sample screw (coated or uncoated, as received) shall be clamped in a mating, split, threaded die or other device so that the clamped portion of the screw is not damaged and at least two full threads project above the clamping device and at l
40、east two full-form threads exclusive of point are held within the clamping device. A threaded insert with a blind hole may be used in place of the clamping device (see Figure 1) provided the hole depth is such as to ensure that breakage occurs beyond the point. By means of a suitable calibrated torq
41、ue-measuring device (in accordance with ISO 898-7:1992, 3.2.2), torque shall be applied to the screw until failure occurs. The screw shall meet the minimum torsional strength requirements given in Table 3. DIN EN ISO 2702:2011-08 EN ISO 2702:2011 (E) 8 Table 3 Torsional strength Thread Minimum torsional strength Nm ST2,2 0,45 ST2,6 0,9 ST2,9 1,5 ST3,3 2,0 ST3,5 2,7 ST3,9 3,4 ST4,2 4,4 ST4,8 6,3 ST5,5 10,0 ST6,3 13,6 ST8 30,5 ST9,5 68,0 DIN EN ISO 2702:2011-08 EN ISO 2702:2011 (E) 9 Bibliography 1 ISO 1478, Tapping screws thread DIN EN ISO 2702:2011-08 EN ISO 2702:2011 (E) 10
