1、August 2005DEUTSCHE NORM 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-
2、Normen).ICS 21.040.20; 21.040.30!$VcQ“1516446www.din.deDDIN 3858Whitworth pipe threads for pipe couplings Parallel internal threads and taper external threads DimensionsWhitworth-Rohrgewinde fr Rohrverschraubungen Zylindrisches Innengewinde und kegeliges Auengewinde MaeSupersedesDIN 3858:1988-01www.
3、beuth.deDocument comprises 11 pagesIn case of doubt, the German-language original should be consulted as the authoritative text.DIN 3858:2005-08 2 Contents Page Foreword 3 1 Scope 3 2 Normative references 3 3 Terms and definitions . 3 4 Dimensions, designation 4 4.1 General 4 4.2 Designation 5 Annex
4、 A (informative) Explanatory notes 11 DIN 3858:2005-08 3 Foreword This standard has been prepared by Section B Gewinde of the Normenausschuss Technische Grundlagen (Fundamental Technical Standards Committee). It supersedes DIN 3858:1988-01 from which it differs in that it has been editorially revise
5、d and references have been updated (see Amendments). Amendments This standard differs from DIN 3858:1988-01 as follows: a) Some terms have been changed in line with current terminology. b) References have been updated. c) The standard has been editorially revised. Previous editions DIN 3858: 1970-08
6、, 1988-01 1 Scope This standard applies to assemblies of taper external threads on pipe couplings and screw plugs with type C stud ends as in DIN 3852-2 and type Z tapped holes with parallel internal thread as in DIN 3852-2. See DIN EN 10226-1 for Whitworth pipe threads for threaded pipes and fittin
7、gs. 2 Normative references The following reference 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. DIN 2244, Screw threads
8、 Terms and screw thread elements for parallel screw threads DIN 3852-2, Stud ends and tapped holes with pipe thread, for use with compression couplings, valves and screw plugs Dimensions DIN EN 10226-1, Pipe threads where pressure-tight joints are made on the threads Part 1: Taper external threads a
9、nd parallel internal threads Dimensions, tolerances and designation DIN EN ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads Part 1: Dimensions, tolerances and designation 3 Terms and definitions For the purposes of this standard the terms and definitions given in DIN 2
10、244 and DIN EN 10226-1 apply. DIN 3858:2005-08 4 4 Dimensions, designation 4.1 General The nominal dimensions and the profile of parallel internal threads and taper external threads at the gauge plane as specified here are identical with those of the threads specified in DIN EN 10226-1, except that
11、taper external threads have a shorter accommodation length. The dimensions are given in Tables 1, 2 and 3. 4.1.1 Parallel internal thread (Rp) The profile of parallel internal threads is identical with that specified in DIN EN ISO 228-1. P = mm4,25 in threads of Numbermm25,4H = 0,960 491 P H1 = 0,64
12、0 327 P R = 0,137 329 P Figure 1 Profile of parallel internal thread DIN 3858:2005-08 5 4.1.2 Taper external thread (R) (taper 1:16) P = mm4,25in threads of Numbermm25,4h = 0,960 237 P h1= 0,640 327 P r = 0,137 278 P Key 1 Gauge plane 2 Thread axis Figure 2 Profile of taper external thread; position
13、 of gauge plane 4.2 Designation Designation of a size Whitworth taper pipe external thread (R) of tolerance class 1: Pipe thread DIN 3858 R 1/2 1 Designation of a size parallel Whitworth pipe internal thread (Rp): Pipe thread DIN 3858 Rp 1/2 DIN 3858:2005-08 6 Table 1 Nominal dimensions Dimensions i
14、n millimetres 1 2 3 4 5 6 7 8 9 10 Gauge length Major diameter Pitch diameter Minor diameter Pitch Number of threads in 25,4 mmHeight of thread Radius Useful thread length Thread size a d = D d2 = D2 d1 = D1 P h1 = H1 r = R l11/8 3 9,728 9,147 8,566 0,907 28 0,581 0,125 5,5 1/4 4,5 13,157 12,301 11,
15、445 1,337 19 0,856 0,184 8,2 3/8 4,5 16,662 15,806 14,950 1,337 19 0,856 0,184 8,2 1/2 5 20,955 19,793 18,631 1,814 14 1,162 0,249 10 3/4 6 26,441 25,279 24,117 1,814 14 1,162 0,249 11 1 7 33,249 31,770 30,291 2,309 11 1,479 0,317 13,4 1 1/4 7,5 41,910 40,431 38,952 2,309 11 1,479 0,317 13,9 1 1/2 7
16、,5 47,803 46,324 44,845 2,309 11 1,479 0,317 13,9 Key 1 Parallel internal thread 2 Taper external thread 3 Reference plane aGiven a maximum a, internally threaded parts shall make allowance for accommodating external pipe threads up to length l1. bGiven a minimum of a, internal threads with free run
17、-out may have a reduced length of useful thread, but not less than 80 % of l1. Figure 3 Useful thread lengths (internal and external threads) DIN 3858:2005-08 7 Key 1 Maximum useful thread length (not less than l1) 2 Washout thread 3 Maximum accommodation length of internal thread, at hand-tight eng
18、agement 4 Wrenching length 5 Gauge plane (dimensions identical with the nominal dimensions given in Table 1) a Gauge length b Assembly length c Length equivalent to positive tolerance on internal thread e Incomplete thread due to undersize of semi-finished product Figure 4 Terms relating to componen
19、ts with taper external thread DIN 3858:2005-08 8 Table 2 Tolerances, limits of size and assembly lengths for external threads (R), for tolerance class 1 (standard type)1)1 2 3 4 5 6 7 8 9 Gauge length a Assembly length Useful thread length l1 minimum Tolerances Limits of size b for for Thread size T
20、urns of thread mm maximummm minimummm Turns of thread mm maximum gauge length mm minimum gauge length mm 1/8 1 0,9 3,9 2,1 2 3/4 2,5 6,4 4,6 1/4 1 1,3 5,8 3,2 2 3/4 3,7 9,5 6,9 3/8 1 1,3 5,8 3,2 2 3/4 3,7 9,5 6,9 1/2 1 1,8 6,8 3,2 2 3/4 5,0 11,8 8,2 3/4 1 1,8 7,8 4,2 2 3/4 5,0 12,8 9,2 1 1 2,3 9,3 4
21、,7 2 3/4 6,4 15,7 11,1 1 1/4 1 2,3 9,8 5,2 2 3/4 6,4 16,2 11,6 1 1/2 1 2,3 9,8 5,2 2 3/4 6,4 16,2 11,6 1) Tolerance class 1 applies to the standard type and tolerance class 2 to short type stud ends as specified in DIN 3852-2. DIN 3858:2005-08 9 Table 3 Tolerances, limits of size and assembly length
22、s for external threads (R), for tolerance class 2 (short type) 1)1 2 3 4 5 6 7 8 9 Gauge length a Assembly length Useful thread lengthl1 minimum Tolerances Limits of size b for for Thread size Turns of thread mm maximummm minimummm Turns of thread mm maximum gauge length mm minimum gauge length mm 1
23、/8 0 1 0 0,9 3 2,1 2 3/4 2,5 5,5 4,6 1/4 0 1 0 1,3 4,5 3,2 2 3/4 3,7 8,2 6,9 3/8 0 1 0 1,3 4,5 3,2 2 3/4 3,7 8,2 6,9 1/2 0 1 0 1,8 5 3,2 2 3/4 5,0 10,0 8,2 3/4 0 1 0 1,8 6 4,2 2 3/4 5,0 11,0 9,2 1 0 1 0 2,3 7 4,7 2 3/4 6,4 13,4 11,1 1 1/4 0 1 0 2,3 7,5 5,2 2 3/4 6,4 13,9 11,6 1 1/2 0 1 0 2,3 7,5 5,2
24、 2 3/4 6,4 13,9 11,6 For 1), see page 8. DIN 3858:2005-08 10 Table 4 Tolerances for internal threads (Rp) 1 2 3 4 Tolerances on major diameter, pitch diameter and minor diameter c Tolerances Thread size mm Turns of thread mm 1/8 + 0,107 0 + 2 0 + 1,8 0 1/4 + 0,125 0 + 1 1/2 0 + 2 0 3/8 + 0,125 0 + 1
25、 1/2 0 + 2 0 1/2 + 0,142 0 + 1 1/4 0 + 2,3 0 3/4 + 0,142 0 + 1 1/4 0 + 2,3 0 1 + 0,180 0 + 1 1/4 0 + 2,9 0 1 1/4 + 0,180 0 + 1 1/4 0 + 2,9 0 1 1/2 + 0,180 0 + 1 1/4 0 + 2,9 0 DIN 3858:2005-08 11 Annex A (informative) Explanatory notes The taper pipe threads specified in this standard are designed wi
26、th shorter thread lengths than the Whitworth pipe threads specified in DIN EN 10226-1; i.e. gauge length a is shorter than that specified in DIN EN 10226-1. The major, pitch and minor diameters of parallel internal threads as specified here have been assigned only positive tolerances, which ensures
27、a maximum accommodation length for taper external threads complying with this standard. While the profile of internal pipe threads is identical with that specified in DIN EN ISO 228-1, different specifications have been given for the limits of size. This requires the designation of threads complying
28、 with this standard to be supplemented by “DIN 3858”. A smaller clearance between the crests and larger thread overlaps are due to minor diameter tolerances that are smaller than specified in DIN EN ISO 228-1. The pipe threads specified in this standard are designed for compression couplings with ty
29、pe C stud ends and type Z tapped holes complying with DIN 3852-2. Since two types (standard and short) have been specified for type C taper stud ends in DIN 3852-2, this standard assigns to gauge length a plus/minus tolerances for tolerance class 1 (standard type) and minus tolerances for tolerance
30、class 2 (short design). All other valves and fittings used in domestic installations shall have threads complying with DIN EN 10226-1. On no account shall the long taper external threads as specified in DIN EN 10226-1 be screwed into a component with shortened internal thread as specified in this standard.
