1、October 2007DEUTSCHE NORM Translation by DIN-Sprachendienst.In case of doubt, the German-language original should be consulted as the authoritative text.English price group 6No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beut
2、h Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 21.060.20!$Z“1559425www.din.deDDIN 267-24Fasteners Technical delivery conditions Part 24: Hardness classes for nuts without specified proof load valuesMechanische Verbindungselemente Technische
3、 Lieferbedingungen Teil 24: Hrteklassen fr Muttern ohne festgelegte PrfkrfteSupersedesDIN 267-24:1983-08www.beuth.deDocument comprises pages7DIN 267-24:2007-10 Contents Page Foreword. 3 Introduction 4 1 Scope . 5 2 Normative references . 5 3 Designation 6 4 Materials. 6 5 Mechanical properties 7 6 T
4、esting . 7 6.1 Hardness testing. 7 6.2 Test of surface condition (surface integrity) 7 7 Marking 7 7.1 Marking of hardness class. 7 7.2 Marking of nuts with left-hand thread 7 2 DIN 267-24:2007-10 Foreword This standard has been prepared by Technical Committee NA 067-02-02 AA Mechanische Eigenschaft
5、en fr Muttern aus Stahl of the Normenausschuss Mechanische Verbindungselemente (Fasteners Standards Committee). Detailed explanatory information relating to the tightening and loadability of bolt-nut assemblies is given in the National Foreword and Annex to DIN EN 20898-2. Amendments This standard d
6、iffers from DIN 267-24:1983-08 as follows: a) The normative references have been updated. b) The length of the foreword and introduction has been substantially reduced. c) The term “property class” has been replaced by “hardness class”: d) The additional symbol “2” designating that the use of Thomas
7、 steel is prohibited has been deleted. e) In the “Materials” clause, the materials are no longer dealt with separately according to the type of working. Previous editions DIN 266: 1931x-03 DIN 267: 1940-06, 1943-01, 1954-01, 1960-12 DIN 267-1: 1937-04 DIN 267-2: 1937-04 DIN 267-4: 1968-05, 1971-10 D
8、IN 267-24: 1983-08 DIN 589: 1931-07, 1934-01 DIN Kr 550: 1936-03 3 DIN 267-24:2007-10 Introduction This standard contains hardness classes for nuts whose properties (usually the shape and dimensions) are such that they cannot be assigned definite load values but can only be classified according to t
9、heir hardness and marked accordingly. In Germany there is a demand for hardness classes to DIN 267-24 for nuts, but as yet there has been no corresponding standardization activity at the international level. 4 DIN 267-24:2007-10 1 Scope This standard contains hardness classes for nuts which do not h
10、ave to withstand specified proof loads. The hardness classes specified have been classified according to minimum hardness values from which, however, no conclusions can be drawn with regard to the loadability of the nuts or their resistance to stripping. The functional properties of nuts depend on t
11、heir form. This standard does not apply to the following: nuts subjected to specified proof loads to DIN EN 20898-2 and DIN EN ISO 898-6; prevailing torque-type nuts to DIN EN ISO 2320; nuts with special requirements, such as weldability, corrosion resistance (see DIN EN ISO 3506-2), high-temperatur
12、e strength (i.e. at temperatures over +300 C) or low-temperature toughness (i.e. at temperatures below 50 C (see DIN 267-13). NOTE Nuts made of free-cutting steel shall not be used at temperatures over +250 C. 2 Normative references The following reference documents are indispensable for the applica
13、tion 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. DIN 267-13, Fasteners Technical delivery conditions Part 13: Parts for bolt/nut assemblies with specific mechanical p
14、roperties for use at temperatures ranging from 200 C to +700 C DIN EN 20898-2, Mechanical properties of fasteners Part 2: Nuts with specified proof load values; coarse pitch thread DIN EN ISO 898-6, Mechanical properties of fasteners made of carbon steel and alloy steel Part 1: Bolts, screws and stu
15、ds DIN EN ISO 2320, Prevailing torque type steel nuts Mechanical and performance properties DIN EN ISO 3506-2, Mechanical properties of corrosion-resistant stainless steel fasteners Part 2: Nuts DIN EN ISO 6157-2, Fasteners Surface discontinuities Part 2: Nuts DIN EN ISO 6506-1, Metallic materials B
16、rinell hardness test Part 1: Test method DIN EN ISO 6507-1, Metallic materials Vickers hardness test Part 1: Test method DIN EN ISO 18265, Metallic materials Conversion of hardness values 5 DIN 267-24:2007-10 3 Designation The hardness classes for nuts according to this standard are denoted by a com
17、bination of numbers and letters as shown in Table 1. The number indicates 1/10 of the minimum Vickers hardness; the letter H stands for hardness. Table 1 Symbols Hardness class symbol 11H 14H 17H 22H Vickers hardness HV 5 min. 110 140 170 220 4 Materials Tables 2 and 3 specify limiting values for th
18、e chemical composition of steel. Alloyed steel is permitted. Table 2 Chemical composition of steel (except free-cutting steel) Chemical composition in % (m/m) (product analysis)aCMn P S Hardness class max.min.max.max.11H 0,50 0,110 0,150 14H 0,50 0,110 0,150 17H 0,58 0,30 0,060 0,150 22H 0,58 0,30 0
19、,048 0,058 aChips for the product analysis shall be taken uniformly over the whole cross section. Nuts of hardness class 22H shall be quenched and tempered. Table 3 Chemical composition of free-cutting steel Chemical composition in % (m/m) (product analysis)aCMn P S Hardness class max.min.max.max.11
20、H, 14H, 17H 0,50 0,12 0,35 0,34 aChips for the product analysis shall be taken uniformly over the whole cross section. 6 DIN 267-24:2007-10 7 5 Mechanical properties The mechanical properties in Table 4 shall apply for testing at room temperature. Table 4 Mechanical properties Hardness class Mechani
21、cal property 11H 14H 17H 22H min.110 140 170 220 Vickers hardness HV 5 max.185 215 245 300 min.105 133 162 209 Brinell hardness HBW 30 max.176 204 233 285 Conversion of hardness values according to DIN EN ISO 18265. 6 Testing 6.1 Hardness testing Hardness testing shall be according to Vickers or Bri
22、nell. Vickers hardness testing shall be to DIN EN ISO 6507-1. Brinell hardness testing shall be to DIN EN ISO 6506-1. The hardness shall be measured on one bearing surface of the nut. Measurements shall be taken at three places spaced 120 apart, and the hardness taken as the mean of these values. In
23、 cases of doubt, the hardness test according to Vickers shall be the reference method. 6.2 Test of surface condition (surface integrity) Testing of the surface condition shall be according to DIN EN ISO 6157-2. 7 Marking 7.1 Marking of hardness class For nuts M5 and the hardness class 22H, marking with the symbol denoting the hardness class is obligatory. 7.2 Marking of nuts with left-hand thread Nuts with left-hand thread are recommended to be marked according to DIN EN 20898-2 if the type and size of the nut is such that this is technically feasible.
