1、IS0 Metric Trapezoidal Screw Thread Profiles Metrisches ISO-Trapezgewinde; Gewindeprofile - DIN 103 Part 1 For connection with IS0 Standard 2901 -1977 issued by the International Organization for Standardization (ISO), see Explanations. 13 2 3 4 5 6 7 8 9 Dimensions in mm 2,799 1,400 0,75 0,549 3,73
2、2 1,866 1 0,732 5,598 2,799 13 1,098 7,464 3,732 2 1,464 9,330 4,665 2.5 1,830 11,196 5,598 3 2,196 13,062 6,531 335 2,562 14,928 7,464 4 2,928 16,794 8,397 4.5 3,294 1 Basic profile The basic profile is the theoretical profile to which the basic dimensions of the outside, pitch and minor diameters
3、are related. The clearances on the outside and minor diameters (see Section 2) and the basic allowances for the pitch diameter (see Section 3) are referred to these basic dimensions. 16 18 20 22 24 28 32 36 40 44 D = d Outside diameter of thread D2 = ci2 Pitch diameter of thread DI = dl Minor diamet
4、er of thread P Pitch of single-start and multiple-start thread H Height of fundamental triangle Hl Thread depth of basic profile 29,856 14,928 8 5,856 33,588 16,794 9 6,588 37,320 18,660 10 7,320 41,052 20,526 11 8,052 44,784 22,392 12 8,784 52,248 26,124 14 10,248 59.71 2 29,856 16 11,712 67,176 33
5、,588 18 13,176 74,640 37,320 20 14,640 82,104 41,052 22 16,104 Figure 1. Basic profile Table 1. Basic profile dimensions I I Pitch P I 0,366 P H Hl I 1,866 P I 0,93/32 P I 0,5 P 10 12 14 18,660 22,392 26,124 9,330 11,196 13,062 5 6 7 3,660 4,392 5,l 24 Continued on pages 2 to 4 Explanations on pages
6、 4 and 5 Vertr.-Nr. 0105 Alleinverkauf der Normen durch Eeuth Verlag GmbH. Berlin 30 und Kln 1 09.79 Page 2 DIN 103 Part 1 Table 2. Nominal profile dimensions P a, H4 = h3 RI max 13 0,15 099 0,075 O, 1 25 0,125 2 0.25 1,25 3 0,25 1.75 4 0.25 2.25 0,125 5 0,25 2.75 0,125 6 05 385 0,25 7 03 4 0.25 8 0
7、.5 4,5 0.25 9 0,s 5 0,25 10 03 5.5 0,25 12 0.5 63 0.25 14 1 8 0.5 16 1 9 03 18 1 10 05 20 1 11 0.5 22 1 12 0,s 24 1 13 0,s 28 1 15 0,5 32 1 17 0.5 36 1 19 O, 5 40 1 21 O, 5 44 1 23 O, 5 I 2 Nominal profiles These profiles, to which the allowances and tolerances are referred, have prescribed clearanc
8、es on the outside and pitch diameters which are referred to the basic profile (see Fig. 1). R2 rnax 0,15 0,25 0.25 0.25 0.25 O, 5 O, 5 O. 5 O, 5 O, 5 05 1 1 1 1 1 1 1 1 1 1 1 Dl Hl = 0,5P H4 = d - 2H1= d - P Hi + U, = 0,5 P + U, h3 =Hi+ac=0,5P+a, H1 2 =0,25P =- 2 04 =d+2ac d3 =d-2h3 a, Clearance 2)
9、RI = max. 0.5 R2 =max.a, d2 = Dz = d - 22 = d - 0,5P Figure 2. Profiles for bolt and nut thread with clearance on the outside and minor diameter and without flank clearance (nominal dimensions) 1) The provision of radiusing R1 or a chamfer on the outside diameter of the bolt thread is recommended. 2
10、) The subscript c signifies crest. 3) The maximum permissible edge radiusing on the outside diameter of the nut thread resulting from wear of the new sharp-edged tool at this point shall not exceed dimension a,. DIN 103 Part 1 Page 3 3 Profiles for threads with flank clearance These profiles derive
11、from the nominal profiles and the basic allowance for the pitch diameter. s = 0.26795 Ao A, = Basic allowance (= upper allowance) for bolt thread on pitch diameter. For other dimension letters (see Fig. 2) Figure 3. Profiles for bolt and nut thread with clearance on outside and minor diameter and wi
12、th flank clearance (nut basis system) 4 Profiles for multiple-start threads (The profile shown is that of a two-start bolt thread) Figure 4. Profiles for multiple-start threads P, Lead Distance along the pitch diameter line between adjacent equal- directed flanks of the same thread. P Pitch Distance
13、 along the pitch diameter line between adjacent equal- directed flanks. Multiple-start (n-start) threads have the same prof le as single-start threads having lead Ph = Pitch P. Only those values which are accepted for the lead P (equal to pitch P) of single-start threads may be chosen for the pitch
14、P of multiple-start threads. The multiple of the pitch P of multiple-start threads need not however correspond with a lead value accepted for single-start threads. 5 Profile variations In the case of rolled bolt threads, the profile at the minor diameter may be modified in order to obtain the increa
15、sed radiusing at the root of the thread which this process requires. The minor diameter of the bolt thread may in this case be made smaller than the nominal diameter dg by 0.1 5 . P. When trapezoidal screw threads are cut by means of straight-flank tools it is possible for variations from the flank
16、form dictated by the nominal profile to occur. Such variations are generally permissible. In special cases (involving steep lead angles; increased precision) it is recommended that agreement should be reached on the manufacturing method (position of the generating lines on the tool) and hence the fl
17、ank form of the bolt and nut threads and the corresponding gauges uniformly defined. In these cases the rules of worm geometry according to DIN 3975 (October 1976 issue, Section 3.6) apply, .e. tools and gauges must be manufactured by the same method. It is not possible to specify the value of the l
18、ead angle for these special cases because it is dependent on a number of different factors. As a guide, the lower limit of 8“ can be assumed for milled trapezoidal threads and 6“ for ground trapezo ida I thread s. l), 2) and 3) See page 2 Page 4 DIN 103 Part 1 Further standards DIN 103 Part 2 DIN 10
19、3 Part 3 DIN 103 Part 4 DIN 103 Part 5 DIN 103 Part 6 DIN 103 Part 7 DIN 103 Part 8 DIN 103 Part 9 IS0 metric trapezoidal screw thread; general plan IS0 metric trapezoidal screw thread; allowances and tolerances for trapezoidal screw threads of general purpose IS0 metric trapezoidal screw thread; no
20、minal dimensions IS0 metric trapezoidal screw thread; limiting sizes for nut threadsfrom 8 to 100 mm nominal diameter IS0 metric trapezoidal screw thread; limiting sizes for nut threadsfrom 105 to 300 mm nominal diameter IS0 metric trapezoidal screw thread; limiting sizes for bolt threads from 8 to
21、100 mm nominal diameter IS0 metric trapezoidal screw thread; limiting sizes for bolt threads from 105 to 300 mm nominal diameter (Preliminary Standard) IS0 metric trapezoidal screw thread; gauges for bolt and nut threads, gauge dimensions and construction features Explanations In Sections 1 and 2 th
22、is Standard is in complete agreement factually with the IS0 Standard 2901-1977 issued by the International Organization for Standardization (ISO). IS0 metric trapezoidal screw threads; Basic profile and maximum-material-profile. Sections 3 and 4 of this Standard dealing with profiles for threads wit
23、h flank clearance and profiles for multiple-start threads are not contained in the IS0 standard. For profiles for threads with flank clearance the basic nut system has been adopted. To keep the flank overlap the same with all classes of fit, the outside diameter of the bolt thread has been made equa
24、l to the nominal dimension d for all tolerance positions. Therefore for all tolerance positions the same gauges can be used for the outside diameter of the bolt thread. Similarly, the nominal dimension of the minor diameter of the bolt thread has been fixed uniformly by 4 for all tolerance positions
25、. The basic allowance A, has been included in the tolerance on the minor diameter. A note relating specifically to the manufacture of trapezoidal screw threads by rolling has been included. There is no objection to the reduction in the minor diameter of the bolt thread permitted in this way, since t
26、he better surface imparted to the core area and the crystalline structure of the bolt mean that the bolt strength is not impaired. Section 5 of this Standard has been enlarged compared with the IS0 standard, since the same conditions apply to the production of trapezoidal screw threads with large le
27、ad angles as to worm manufacture (see DIN 3975, October 1976 issue, Section 3.6). DIN 103 Part 1 Page 5 previous values for bolt thread tl Alterationscompared with DIN 103 (August 1924 issue), DIN 378 Part 1 and Part 2 (October 1925 issues), DIN 379 (August 1937 issue): The following alterations had
28、 already been indicated in DIN 103 Part 1 (August 1970 issue) in the Explanations and are now repeated for a better understanding of earlier documentation. In conformity with IS0 2901 the crest clearances a, have been altered compared with the previous finish of trapezoidal screw thread, because it
29、had been decided during the preparation of the IS0 standard to lay down a uniform value for the crest clearance a, on the outside and minor diameters of the thread in conformity with the standards of the USSR and of the countries using the Anglo-American units. The Table below presents a comparison
30、of the previous values according to DIN 103, DIN 378 and DIN 379 with the new values. new values for and nut threads h3 = H4 previous 2,75 3.25 3,75 4,25 4.75 5.25 6,25 83 10.5 Lead 2.75 3.5 4 495 5 5,5 65 9 11 a Ib 24 32 40 new a, 11 12 15 16 19 20 2 3 4 0,25 0.25 0.25 0,25 0,25 0,25 5 6 7 0,25 0,2
31、5 0,25 0,75 0,75 0,75 8 9 10 0.25 0.25 0,25 0,75 0,75 0,75 12 16 20 0,75 15 1.5 05 1 1 24 32 40 The depth of bolt thread h3 has been fixed at 0.5 x P + a, and the flank overlap at H1 x 0.5 x P. The Table below compares the thread depth h3 of the bolt thread and H4 of the nut thread as well as the fl
32、ank overlapH1 according to this Standard with the values laid down in the earlier standards DIN 103, DIN 378 and DIN 379. Thread depth Flank overlap previous t2 previous values for nut threads T Lead P new H1 2 3 4 0,75 1,25 1,75 1 1,s 2 1.25 1,75 2.25 1,25 1,75 2.25 1 13 2 2 2.5 3 23 3 395 2,25 2.75 3,25 3,75 425 4.75 3,5 4 4.5 4 4,5 5 10 16 20 575 7 9 6 8 10 5,75 7,5 9,5 12,5 16,5 20.5 13 17 21 11,5 15,5 19,5
