1、September 2009 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).I
2、CS 21.060.10!$i5c“1701864www.din.deDDIN 267-28Fasteners Part 28: Steel screws, bolts and studs with locking coating Technical delivery conditionsEnglish translation of DIN 267-28:2009-09Mechanische Verbindungselemente Teil 28: Schrauben aus Stahl mit klemmender Beschichtung TechnischeLieferbedingung
3、enEnglische bersetzung von DIN 267-28:2009-09Elments de fixation Partie 28: Vis et goujons en acier avcec revtement serrant Spcifications techniquesTraduction anglaise de DIN 267-28:2009-09SupersedesDIN 267-28:2004-01 andDIN 267-28 Corrigendum1:2004-11www.beuth.deDocument comprises pagesIn case of d
4、oubt, the German-language original shall be considered authoritative.1109.10DIN 267-28:2009-09 Contents Page Foreword. 3 1 Scope . 4 2 Normative references . 4 3 Terms and definitions 4 4 Dimensions and designation. 5 5 Requirements 7 6 Testing . 8 7 Miscellaneous functions 10 8 Storage. 11 2 DIN 26
5、7-28:2009-09 Foreword This standard has been prepared by Working Committee NA 067-02-08 AA Schrauben und Muttern mit klebenden und klemmenden Beschichtungen of the Normenausschuss Mechanische Verbindungselemente (Fasteners Standards Committee). Amendments This standard differs from DIN 267-28:2004-0
6、1 and DIN 267-28 Corrigendum 1:2004-11 as follows: a) corrigendum 1 has been incorporated; b) bright-finished and coated surfaces have been added to the scope of the standard; c) normative references have been revised and updated; d) examples of designation have been added; e) the scope of the stand
7、ard has been extended to include stainless and high temperature resistant steels; f) restrictions on the corrosion resistance properties have been added; Previous editions DIN 267-28: 1990-03, 2004-01 DIN 267-28 Corrigendum 1: 2004-11 3 DIN 267-28:2009-09 1 Scope This standard specifies functional c
8、haracteristics of locking coatings applied on steel screws, bolts and studs (“bolts” for short) with ISO metric screw thread as in DIN ISO 261, with a nominal thread diameter between 3 mm and 16 mm (coarse-pitch), with a nominal thread diameter between 8 mm and 16 mm (fine-pitch), assigned to proper
9、ty classes in accordance with DIN EN ISO 898-1, DIN EN ISO 3506-1 and DIN 267-13, with bright-finished and coated surfaces, for use at service temperatures ranging from 50 C to 120 C and, for special applications, up to 150 C or 200 C. This standard does not specify any requirements for further mach
10、ining of the thread in order to incorporate a locking device. 2 Normative references The following references 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
11、 any amendments) applies. DIN 267-13, Fasteners Technical delivery conditions Part 13: Parts for bolted connections with specific mechanical properties for use at temperatures ranging from 200 C to +700 C DIN EN 20273, Fasteners Clearance holes for bolts and screws DIN EN ISO 898-1, Mechanical prope
12、rties of fasteners made of carbon steel and alloy steel Part 1: Bolts, screws and studs DIN EN ISO 3506-1, Mechanical properties of corrosion-resistant stainless steel fasteners Part 1: Bolts, screws and studs DIN EN ISO 4032, Hexagon nut, style 1 Product grades A and B DIN EN ISO 4753, Fasteners En
13、ds of parts with external ISO metric thread DIN EN ISO 7089, Plain washers Normal series Product grade A DIN EN ISO 8673, Hexagon nut, style 1, with metric fine-pitch thread Product grades A and B DIN ISO 261, ISO general purpose metric screw threads General plan ISO 4017, Hexagon head screws Produc
14、t grades A and B 3 Terms and definitions For the purposes of this document, the following terms and definitions apply: 4 DIN 267-28:2009-09 3.1 locking coating adhesive coating which is designed to prevent disengagement when the bolt is tightened. The bolt may be coated over its whole circumference
15、(R) or the coating applied locally as strips or spots (F) 3.2 screw-in torque Mintorque measured when a bolt is driven into a test nut 3.3 tightening torque MAtorque required to generate the required preload 3.4 loosening torque Mouttorque measured after the breakaway point when unscrewing bolts wit
16、h a locking coating 4 Dimensions and designation 4.1 Standard coating Unless otherwise specified, the coating shall cover a zone, measured from the bolt end, of length equal to 1,5 d 2 P. The first two or three turns of thread shall be free from coating material to facilitate bolting (see Figure 1).
17、 Coating residue in these turns is permitted unless this adversely affects the specified function and/or use of the bolt. Key d Nominal thread diameter lbZone to be covered by the coating a Two or three turns of thread left uncoated P Pitch Figure 1 Length and position of coated zone on bolts with s
18、tandard coating 4.2 Non-standard coating If, for design reasons, a different length lband/or a different distance a between the coating and the end of the bolt is required (see Figure 2), both dimensions shall be indicated in the standard designation (see 4.3). For dimension lba tolerance equal to 2
19、 P applies. 5 DIN 267-28:2009-09 Key lbLength of coated zone a Distance of coated zone from bolt end Figure 2 Length and position of coated zones on bolts with non-standard coating 4.3 Designation The designation of bolts with a locking coating conforming to this standard shall include the following
20、 items, given in the order below: symbol KL denoting a locking coating (type as designated), KLR denoting the locking coating covering the whole circumference of the bolt, KLF for the locally applied locking coating, service temperature (for bolts suitable for use at temperatures up to 150 C or up t
21、o 200 C), lb(length of coated zone ) a (distance of coated zone from bolt end) in millimetres, where appropriate. Examples of designation EXAMPLE 1 Designation of an M12 steel bolt (M12) with a nominal length, l, of 80 mm (80), of property class 8.8, provided with a locking coating covering the whol
22、e circumference of the bolt (KLR), suitable for use at temperatures up to 120 C: Bolt 1) M12 80 8.8 KLR EXAMPLE 2 Designation of an M12 steel bolt (M12), with a nominal length, l, of 80 mm (80), with a long dog point (LD) as in DIN EN ISO 4753, of property class 8.8, provided with a locking coating
23、(KL), suitable for use at service temperatures up to 150 C, with a length of coated zone, lb, of 30 mm and a distance from the bolt end, a, of 10 mm (30 10): Bolt 1) M12 80 LD 8.8 KL 150 30 10 EXAMPLE 3 Designation of an M12 steel bolt (M12), with a nominal length, l, of 80 mm (80), with a long dog
24、point (LD) as in DIN EN ISO 4753, of property class 8.8, provided with a locally applied locking coating (KLF), suitable for use at service temperatures up to 200 C, with a length of coated zone, lb, of 30 mm and a distance from the bolt end, a, of 10 mm (30 10): Bolt 1) M12 80 LD 8.8 KLF 200 30 10
25、1)Applicable product standard to be designated here. 6 DIN 267-28:2009-09 5 Requirements 5.1 General In processes with molten polyamide coatings suitable for use at service temperatures up to 120 C, short term, local process temperatures of approximately 220 C to 230 C are generated on the coated pa
26、rts. In the case of coatings for service temperatures of 150 C to 200 C, the process temperatures generated can be significantly higher. This can adversely affect the functional properties of coated surfaces. In particular, the corrosion resistance can be impaired. Locking coatings cannot prevent th
27、e assembly from working loose, but they prevent the complete detachment of the individual components. 5.2 Bonding strength Unless the requirements specified in Table 1 are met, the locking coating shall not detach itself from the surface. Where locking coatings are applied on surfaces with incorpora
28、ted and/or additionally applied lubricants, the bonding strength can be adversely affected, which may result in the detachment of the locking coating during the initial engagement or reduce the capability of multiple bolting. Adequate bonding strength is ensured as long as the values specified in Ta
29、ble 1 are maintained after unscrewing the third time (3rddisengagement). If only the first loosening torque is reached, values are subject to agreement between the manufacturer of the coating and the user. 5.3 Test tightening torques 5.3.1 Testing with preload When bolts are tested with preload as s
30、pecified in Clause 6, the limiting values of the test torques at ambient temperature (23 5) C), at 120 C and, for special applications, at 150 C or at 200 C given in Table 1 shall be met. 7 DIN 267-28:2009-09 Table 1 Test torques at ambient temperature, 120 C, 150 C and 200 C (with preload) Screw-in
31、 torque Test tightening torque MAa, bLocking torque Nm 1stengagement MinNm Nm 1stdisengage- ment Mout3rddisengage- ment MoutThread size max. 5.6 5.8 8.8 10.9 12.9 min. min. M3 0,43 0,6 1,2 0,1 0,08 M4 0,9 1,3 2,8 0,12 0,1 M5 1,6 2,6 5,5 0,18 0,15 M6 3 4,5 9,5 0,35 0,23 M8 M8 1 6 11 23 0,85 0,45 M10
32、M10 1,25 10,5 22 46 1,5 0,75 M12 M12 1,25, M12 1,5 15,5 38 79 2,3 1,6 M14 M14 1,5 24 60 125 3,3 2,3 M16 M16 1,5 32 90 195 4,0 2,8 M18 M18 1,5 45 128 280 4,7 3,2 NOTE Torques for thread sizes not included in this table shall be subject to agreement by the supplier. a MA has been determined on the bas
33、is of an overall coefficient of friction ges= 0,12 assuming a 90 % utilization of the minimum yield stress (property classes 5.6 and 5.8) or 0,2 % proof stress (property classes 8.8, 10.9 and 12.9) for the relevant lowest property class. The test tightening torque is only applied after the first eng
34、agement. b For bolts conforming to DIN EN ISO 3506-1 and DIN 267-13, the values for property classes 5.6 and 5.8 apply. 6 Testing 6.1 General When bolts with a locking coating are tested in accordance with subclauses 6.3 and 6.4, the requirements for tests with preload specified in subclause 5.3.1 s
35、hall be complied with. 6.2 Service temperature of bolts with locking coating Bolts with a locking coating are normally designed for use at service temperatures ranging from 50 C to +120 C and, in special applications, from 50 C to +150 C or from 50 C to +200 C. 6.3 Procedure The bolt to be tested sh
36、all be passed through a washer conforming to DIN EN ISO 7089, free from grease, with a hardness between 200 HV and 300 HV, and a bright finish, and through either two distance blocks (see Figure 3) or a spacer sleeve (see Figure 4), and tightened by screwing into a nut at a rate of 30 min1, until th
37、e relevant MAvalue according to Table 1 is reached. The thickness of the blocks or spacer sleeve shall be selected so that the nut thread is in complete contact with the coated zone. During engagement, the maximum screw-in torque shall be measured. After a period of at least 15 seconds, the bolt sha
38、ll be loosened by turning it through 360, followed by a further turn through 360 at a maximum rate of 30 min1, and the maximum loosening torque Moutshall be measured. The bolt shall be fully unscrewed and engaged again, without subjecting the assembly to stress (i.e. without pre-tightening the bolt)
39、. 8 DIN 267-28:2009-09 For tests at a temperature of 150 C or 200 C, the assembly shown in Figure 4 should be used, with washers as in DIN EN ISO 7089 to protect both bolt head and nut. For tests at elevated temperatures, the bolts shall be tightened, heated for one hour to reach test temperature, e
40、xposed to the relevant test temperature for three hours, and then tested within 10 seconds following removal from the oven. When using the test assembly with spacer sleeve, either the bolt or the nut may be turned. Key 1 Washer as in DIN EN ISO 7089 2 Medium series clearance hole as in DIN EN 20273
41、3 Coating 4 Distance block, with a hardness 35 HRC 5 Test nut as in DIN EN ISO 4032 or DIN EN ISO 8673 6 Distance block, with a hardness 35 HRC Figure 3 Test assembly with distance blocks Key 1 Washer as in DIN EN ISO 7089 2 Medium series clearance hole as in DIN EN 20273 3 Coating 4 Spacer sleeve w
42、ith an external diameter 2 d and a hardness 35 HRC 5 Test nut as in DIN EN ISO 4032 or DIN EN ISO 8673 Figure 4 Test assembly with spacer sleeve 9 DIN 267-28:2009-09 6.4 Test specimens and equipment 6.4.1 Test bolt A hexagon screw complying with ISO 4017 M10 6g 402) 8.8 as manufactured shall be used
43、 as the test bolt. 6.4.2 Test nut For the test of bolts with a coarse pitch thread, a nut as in DIN EN ISO 4032, and for bolts with a fine pitch thread, a nut as in DIN EN ISO 8673 shall be used. The test nut shall meet the following requirements: the property class shall be at least equal to that o
44、f the bolt; the thread surface shall be bright or blackened; the thread of the test nut shall be free from oil, grease, burrs and machining chips. Test nuts shall be used once only. The thread shall be produced to 6H tolerance (subject to agreement, the nut may be produced to a closer tolerance). 6.
45、4.3 Test washer The test washer shall meet the requirements specified in DIN EN ISO 7089. The hardness of the washer shall be in the range between 200 HV and 300 HV, and its surface shall be bright and free from grease. 6.4.4 Torque meter Torques shall be determined with a torque meter. The torque m
46、eter to be used shall be a torque wrench or a mechanically driven testing instrument with a limit of accuracy not exceeding 2 % of the upper limit of the given torque range (ultimate value of the measuring range). In arbitration cases, the device shall be chosen so that all values can be read off in
47、 the upper half of the measuring range. 6.4.5 Oven for thermal stability testing For thermal stability tests, an oven ensuring the temperature does not deviate by more than 2 C from the relevant test temperature in the empty usable space shall be used. After reaching the test temperature the oven sh
48、all be charged. The test specimen shall be removed from the oven after the test period has expired. 7 Miscellaneous functions 7.1 Sealing function Apart from their locking capacity, locking coatings of type KLR are also suitable for sealing purposes. Where the locking coating of type KLR is also req
49、uired to seal the thread, testing of the sealing characteristics and requirements regarding the sealing function are subject to agreement. 2)Other thread lengths are permissible provided requirements are met. 10 DIN 267-28:2009-09 11 7.2 Bolting 7.2.1 Nut thread There are no special requirements with regard to the surface roughness of the thread. However, the thread
