1、DEUTSCHE NORM April 1985 UDC 621.882.082.4 I Stub metric trapezoidal screw threads Thread profiles - DIN 380 Part 1 Flaches metrisches Trapezgewinde; Gewi ndeprofile Supersedes November 1975 edition. In keeping with current practice in standards published by the International Organization for Standa
2、rdization (ISO), a comma has been used throughout as the decimal marker. The tread profiles specified in this standard are derived from those of the IC0 metric trapezoidal screw threads as specified in DIN 103 Part 1, and except for the minor diameter, are identical with them. If DIN 103 Part 3 to P
3、art 8 are applied to stub trapezoidal screw threads, it shall be noted that only the diameters and pitches specified in DIN 380 Part 2 shall apply and that all the dimensions associated with the minor diameter and limits of sizes have to be corrected by + 0,4 P. 1 Basic prof le The basic profile is
4、the theoretical profile associated with the basic sizes of the major, pitch and minor diameters. The major and minor diameter clearances (see clause 2) and the basic deviations of the pitch diameter (see clause 3) are applied to these basic sizes. Dimensions in mm D = d = major diameter of screw thr
5、ead D2 = 4 = pitch diameter of screw thread D, = d, = minor diameter of screw thread P = lead of single-start screw thread and pitch of multiple-start screw thread H = height of fundamental triangle H, = height of basic profile as specified in DIN 103 Part 1 H2 = height of basic profile as specified
6、 in this standard Figure 1. Basic profile 0.5 P 0,75 1 1,5 2 2,5 3,5 4 4,5 3 Table 1. Basic prof le dimensions I I I 0,3 P 0,366P 0,473 P 0,25P 0,05 P Ot6 Hi 086 0,732 0,946 03 o, 1 12 1,464 1,892 1 0.2 0.45 0,549 0,710 0,375 0,075 0,9 1,098 1,419 0,75 0,15 1,5 1,830 2,365 1,25 0.25 2,1 2,562 3,311
7、1,75 0,35 2,4 2,928 3,784 2 0.4 2,7 3,294 4.257 2,25 0,45 1,8 2,196 2,838 1,5 0,3 Pitch 1.5 2 3 4 5 6 7 8 9 PI 2,799 1,400 3.732 1,866 5,598 2,799 7,464 3,732 9,330 4,665 11,196 5,598 13,062 6,53 1 14,928 7,464 16,794 8,397 10 12 14 16 18 20 22 24 18,660 9,330 22,392 11,196 26,124 13,062 29,856 14,9
8、28 33,588 16,794 37,320 18,660 41,052 20,526 44,784 22,392 3 3.6 43 5,4 6 6.6 72 42 5 6 7 3,660 4,730 2,s 0,s 4,392 5,676 3 0,6 5,856 7,568 4 0,8 6,588 8,5 14 4.5 0,9 7,320 9.46 5 1 8.052 10,406 5,5 1,1 8,784 11,352 6 1.2 5,124 6,622 3,5 0.7 8 9 10 11 12 Continued on pages 2 to 4 Beulh Verlag GmbH.
9、Berlin 30. has exciusive sale rights for German Standards (DIN-Normen) DIN 380 Part 1 Engl, Price group 5 01.86 Sales No. 0105 Page 2 DIN 380 Part 1 P a, H4 = h, RI may. 1.5 0.15 O -6 0,075 2 0,25 0,85 0,125 3 0,25 1.15 0,125 4 j 0,25 1,45 0,125 5 0,25 1,75 0,125 6 03 23 0,25 8 0.5 2,9 0,25 9 03 3.2
10、 0,25 10 0,5 3,5 0.25 12 0.5 4,1 0.25 14 1 5,2 03 16 1 5,8 05 18 1 6.4 0,s 20 1 7 03 22 1 7,6 0,5 24 1 82 0.5 7 0.5 2,6 0.25 2 Nominal profiles The nominal profiles to which the deviations and tolerances are applied have specified clearances on the major and minor diameters relative to the basic Pro
11、file (see figure 1 ). R2 max. 0.1 5 0,25 0,25 0,25 0,25 05 03 05 0,5 0,5 1 1 1 1 1 1 0,5 3 Profiles of threads with clearance on the flank The profiles with clearance on the flank result from the nominal profiles and the fundamental deviation for the pitch diameter. a = 0,26795 A, A, = fundamental d
12、eviation (= upper deviation) for external thread on pitch diameter For the other dimension letters, see figure 2. Figure 3. Profiles for external and internal threads with clearance on the major and minor diameters and on the flank (standard nut system) 1) It is recommended to provide for a rounding
13、 R1 or a chamfer at the major diameter of the external thread. 2) The index c stands for crest. DIN 380 Part 1 Page 3 With a view to obtaining this clearance, the standard nut system has been selected. In order to obtain the same thread overlap for all fits, the major diameter of the external thread
14、 has been fixed as being equal to the nominal sized for all tolerance positions. This also means having the same gauges for the major diameter of the external thread. In the case of rolled external threads, the profile of the minor diameter may be changed in order to obtain a rounding on . P smaller
15、 in this case. the thread root. The minor diameter d3 of the external thread may be 0,15 4 Profiles for multiple-start threads (The profile shown is of a double-start external thread.) el Ph = P -i P= I lead (axial advance at one turn) pitch (axial distance between two neighbouring flanks being in t
16、he same direction) Figure 4. Profiles for multiple-start threads Multiple-start (n-start) threads have the same profile as single-start threads with the lead Ph = pitch P. For the pitch P of multiple-start screw threads, only the values permitted for the lead P (which is equal to pitch P) of the sin
17、gle-start screw threads may be selected. However, the multiple of the pitch P of the multiple-start screw threads need not correspond to a permitted lead value for single-start screw threads. 5 Profile deviations The shape of the flanks of trapezoidal screw threads may deviate from the basic profile
18、 if they are made using straight- flanked tools. In special cases, (large lead angle; increased accuracy), it is recommended to agree upon the method of manufacture (the position of the generatrix on the tool) and, thus, to fix a standard flank shape of the external and internal threads and the corr
19、esponding gauges. In these cases, the rules of worm geometry as specified in DIN 3975 shall apply, and the tool and gauge shall be made using the same method. It is not possible to indicate the lead angle as it depends on various factors. As a general guide, 8“ and 6“ may be used for milled and grou
20、nd trapezoidal screw threads respectively. Standards referred to DIN 103 Part 1 DIN 103 Part 3 DIN 103 Part 4 DIN 103 Part 5 DIN 103 Part 6 DIN 103 Part 7 DIN 103 Part 8 DIN 380 Part 2 DIN 3975 IS0 metric trapezoidal screw threads; thread profiles IS0 metric trapezoidal screw threads; deviations and
21、 tolerances for general purpose trapezoidal screw threads IS0 metric trapezoidal screw threads; nominal dimensions IS0 metric trapezoidal screw threads; limits of size for internal threads of 8 to 100 mm nominal diameter IS0 metric trapezoidal screw threads; limits of size for internal threads of 10
22、5 to 300 mm nominal dia me ter IS0 metric trapezoidal screw threads; limits of size for external threads of 8 to 100 mm nominal diameter IS0 metric trapezoidal screw threads; limits of size for external threads of 105 to 300 mm nominal diameter Stub metric trapezoidal screw threads; general plan Con
23、cepts and parameters relating to cylindrical worm gears with 90“ shaft angle Other relevant standards DIN 103 Part 9 IS0 metric trapezoidal screw threads; gauges for external and internal threads; gauge dimensions and design features Previous editions DIN 380 Part 1: 11.75 Amendments The following a
24、mendments have been made in comparison with the November 1975 edition. a) The status of the standard is no longer that of a preliminary standard. b) The standard has been editorially revised. Page 4 DIN 380 Part 1 Explanatory notes on DIN 380 Part 1 and Part 2 The stub metric trapezoidal screw threa
25、d covered by this standard is derived from the IS0 metric trapezoidal screw thread as specified in the DIN 103 series of stand- ards, and except for the minor diameter, is identical with it. As with the Stub Acme screw thread specified in ASA B. 1.8, the height of the basic profile H1 has been fixed
26、 at 0,3 P; this means that, compared with the trapezoidal screw thread specified in the DIN 103 series of standards, the minor diameter is increased by 2 X 0,2 P, whilst the major and pitch diameters of the external thread are identical with those of the screw thread specified in the DIN 103 series
27、of standards. The stub metric trapezoidal screw thread offers the followina advantaaes. “ - Tools such as thread chasers and thread rollers which have been used for making the trapezoidal screw threads specified in the DIN 103 series of standards may be used subsequently by grinding down the rollers
28、 or chasers to the thread height required for the stub trapezoidal screw thread. The same measuring equipment may be used for checking the major and pitch diameters as for the trapezoidal screw thread specified in the DIN 103 series of standards, except that the gauge sides of the flank micrometer h
29、ave to be ground down in accordance with the larger minor diameter of the stub trapezoidal screw thread. For the internal thread, the same tap may be used as for the trapezoidal screw thread specified in the DIN 103 series of standards; only the core hole drill is to be of a correspondingly larger d
30、iameter. Thus, the loadbearing parts of the profile of the external thread are narrower than the gaps, and vice versa with the internal thread. The cross section of the stressed threads of the nut is wider than that of the bolt. However, as spindles are generally made of steel and nuts of bronze or
31、plastics, this may be regarded as an advantage as the nut wears more quickly. The screw thread gauges as specified in DIN 103 Part 9 may only be used under certain conditions as follows for gauging the stub metric trapezoidal screw thread: a) the Go screw ring gauge shall be internally ground; b) th
32、e Not Go screw ring gauge may be used under certain circumstances, but the width of the undercut shall be less than, and the minor diameter equal to the pitch diameter; c) the Go screw plug gauge may be used without amend- ment; d) the Not Go screw plug gauge may only be used rarely as the thread ov
33、erlap is too small, as a result of the shortened flanks of the gauge, to enable the plug gauge to be screwed into the internal thread satisfac- torily. If the stub metric trapezoidal screw thread is to be used frequently in a company, new gauges will have to be provided, taking into account the char
34、acteristic features of this screw thread. The stub metric trapezoidal screw tread is very often used in the construction of large gate valves and in the manufacture of screw clamps, for example, as it has considerable higher loadbearing capacity than the screw thread covered by the DIN 103 series of
35、 standards. DIN 380 Part 1 and Part 2 were submitted to ISO/TC I/ SC 3 as a German proposal for a corresponding IS0 Standard. As is was not possible to agree to DIN Standards being adopted without amendment as IS0 Standards, DIN 380 Part 1 and Part 2 were published as preliminary standards. Meanwhil
36、e, the interest of the ISO/TC 1 member bodies in an IS0 Standard on stub metric trapezoidal screw threads waned. Finally, ISO/TC 1 decided to stop work on this item. Since the two standards have proved their value in Germany, their status is no longer that of a preliminary standard. International Patent Classification F 16 I3 33/02
