1、DEUTSCHE NORMEN January 1977 UDC 021.882.082.41.6 I Runouts Undercuts for Trapezoidal Threads, Buttress Threads and Knuckle Threads and other Threads of Coarse Pitch DIN 76 Part 3 Gewindeauslufe, Gewindefreistiche fr Trapez-, Sgen- und Rundgewinde und andere Gewinde mit grober Steigung Dimensions in
2、 mm 1 Scope This Standard applies primarily to threads according to the following DIN standards: For IS0 metric trapezoidal thread, see DIN 103 Part 1 For knuckle thread with clearance and steep flank with pitch 7 mm, see DIN 262 Part 1 For trapezoidal thread, single and two start, with clearance, s
3、ee DIN 263 Part 1 For knuckle thread with clearance and flat flank with pitch 7mm, see DIN 264 Part 1 For flat metric trapezoidal thread, see DIN 380 Part 1 (Preliminary Standard) For knuckle thread, see DIN 405 Part 1 For metric buttress thread, see DIN 513 Part 1 (Preliminary Standard) For rounded
4、 trapezoidal thread, see DIN 30295 Part 1 This Standard may, however, also be used for other standardized and non-standardized threads of coarse pitch. 2 External thread (bolt thread) 2.1 Runouts (x I 2.2 Distance from last full thread to contact face (on parts threaded approximately to head) 2.3 Un
5、dercut Transition angle a over the range between fi and f2 30 to 60 according to method of (to be preferred for trapezoidal thread) Type A regular thread manufacturing. TypeB short TypeC long For dimension table see page 2 For runouts and undercuts for IS0 metric threads according to DIN 13, see DIN
6、 76 Part 1 Continued on pages 2 and 3 Explanations on page 3 einverkauf der Normen durch Beuth Verlag QmbH. Berlin 30 und Kln 1 DIN 76 Tell 3 engl. Preisgr. 4 1.78 Verir.-Nr. O104 COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 2 Table 1. Exter
7、nal thread DIN 76 Part 3 Distance ai I a2 I a3 Runout Thread I XI 1 XS 1 X3 fi pitch P 1 1,5 2 3 4 5 6 7 8 9 10 12 14 16 18 20 22 24 28 36 40 44 32 7,5 16,5 10 22 12,5 27,5 15 33 regulai 4P 4 6 8 12 16 20 24 28 32 36 40 48 56 64 72 80 88 96 112 144 160 176 128 121 4,5 3 6.8 4.5 * 176 5.5 8,3 * 110 I
8、242 96 112 128 - 144 160 176 60 132 72 48 96 70 154 84 56 112 80 176 96 64 128 90 198 108 72 144_ 100 220 120 80 160 110 242 132 88 176 Undercut 3) Iglr i2 max. l regular B short 4) C long 4.5P i 3P I 5.5P 1 h13 I 22,5 27,5 L c cl al E c .- 72 48 99 . td 110 220 i 242 I 1 I I 1) Only for special cas
9、es in which for technical reasons, a short thread distance is necessary. The requirement “short”can 2) In the case of threads made by machining, the long distance should always be adopted. 3) In the case of rolled threads, the diameter of the shoulder is often decisive regarding the feasibility of m
10、anufacturin( the thread close up to the shoulder. Agreements should therefore be reached between manufacturer and customer on the diameter of the shoulder. short undercut requires special tools for thread manufacture. be met only by special measures. 4) Undercut Type B (short) only for special casds
11、 in which for technical reasons, a short undercut is necessary. This 3 Internal thread (nut thread) 3.1 with runout 3.2 with undercut (only for thread with d 8mm) Type D regular TypeE short TypeF long Threaded Mind holes (only for thread with d 5 8mm) b - Usable thread length other dimensions as for
12、 Section 3.1 Transition angle a over the range between fi and fi 30 to 60 according to method of thread manufacturing 5) Recommended permissible variations for the calculated dimension t: +E5 6) is usua11y1200-; in special cases 900. COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed
13、 by Information Handling ServicesDIN 76 Part 3 Page 3 g H 13 Table 2. Internal thread r Thread pitch P 1 195 2 3 4 5 6 7 8 9 regular short I long D regular E short7) 6P 4P 10P 5P 3P 6 4 10 5 3 F longa) 8,5P 8,s 16 96 64 160 I 80 18 108 72 180 20 120 80 , 200 36 40 44 187 204 168 112 192 216 1 144 36
14、0 80LC_ 108 -.- i 306 240 160 400 200 I 120 i 340 264 I 176 440 220 I 132 j 374 Undercut f2 1 regular I E short7) F long? 8,:; 1 1 1:; 42,5 51 30 72 76,5 85 238 272 1 45 108 50 120 60 1 144 70 1 168 192 140 336 160 1 384 306 1 180 432 340 I 200 I 480 - 374 1 220 i 528 I d+l E I- d + 1,5 P d + 2,5 1
15、7) Blind hole projection e2 and undercut Type E only for special cases in which for technical reasons, such a provision 8) The blind hole projection e3 and undercut Type F apply to those cases where thread-cutting taps are used or is absolutely necessary; the specification “short” involves very high
16、 manufacturing costs. materials of high strengths are involved. Notes: In the case of values for el to e3, regard was had to the various manufacturing methods for internal threads and provision made for adequate depth for collecting the cuttings. The values for the width of the blind hole projection
17、 or for the undercut were selected to enable thread-cutting tools to be used for “long”. The regular case involves repeated cutting with sets of taps. “Short” necessitates in every case multiple cutting with specially manufactured sets of tools. In the case of the blind hole projection “long”, also,
18、 thread-cutting taps should only be used for materials of low strength or with fine threads. As far as possible, only undercuts should be used for trapezoidal threads. 4 Examples of entry for drawings In drawings the dimensioning of runouts and undercuts can be superseded by an appropriate reference
19、 to DIN 76 Part 3. 4.1 External thread Examples: Runout x1 according to DIN 76 Part 3 Thread distance al according to DIN 76 Part 3 Undercut Type B according to DIN 76 Part 3 4.2 Internal thread Examples: Blind hole projection el according to DIN 76 Part 3 Undercut Type E according to DIN 76 Part 3
20、Explanations This Standard has been drawn up to conform very closely to DIN 76 Part 1 (September 1975ssue). In so doing, the provisions of standard DIN 5614 on thread grooves for trapezoidal and knuckle threads for rail vehicles were also taken into account in order thereby to enable the Normenausschuss Schienenfahrzeuge (Committee on Rail Vehicles) to withdraw DIN 5614. In other respects, the Explanations in DIN 76 Part 1 also apply as appropriate to this Standard. COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling Services
