1、I L I UDC 621.882.082.4 : 621.753.1 DEUTSCHE NORMEN April 1977 IS0 Metric Trapezoidal Screw Thread DIN Allowances and Tolerances 103 for Trapezoidal Screw Threads of General Purpose Part 3 Metrisches ISO-Trapezgewinde, Abmasse und Toleranzen fr Trapezgewinde allgemeiner Anwendung This Standard confo
2、rms essentially with the International Standard IS0 2903-1977 issued by the International Organization for Standardization (ISO). I SO metric trapezoidal screw threads; tolerances The pitch diameter tolerances laid down in this Standard do not apply to trapezoidal screw threads on spindles or screws
3、 which have to meet special requirements in regard to the trapezoidal screw thread, e.g. trapezoidal screw threads on leadscrews. Contents 1 Introduction 1 6 Outsideand minor diameter tolerances 3 2 Designations 1 7 Pitch diameter tolerances . 5 3 Tolerance grades . 1 8 Recommended tolerance fields
4、. 7 4 Tolerance positions (basic allowances) . 1 9 Formulae . 7 5 Lengths of engagement . 2 10 Multiplestart trapezoidal screwthread 8 Page Page 1 Introduction 3 Tolerance grades For single-start IS0 metric trapezoidal screw threads the same tolerance system is to be used as for IS0 metric fastening
5、 thread. Therefore for threads up to 6 mm pitch, this Standard contains extracts from DIN 13 Part 14 and Part 15, and also,for threads with Table 1. Tolerance grades for outside, pibh diameter and minor diameter pitches above 6 mm, supplementary information regarding of nut thread basic allowances e
6、, lengths of engagement and tolerances. The basic allowances c have been newly included. For trapezoidal screw threads other preferred tolerance fields than for fastening threads are recommended. 2 Designations The full designation of a thread contains information on the thread system, an indication
7、 of the nominal dimension of the thread, and gives the symbol for the thread tolerance. The thread designation for IS0 metric trapezoidal screw threads isgiven in DIN 103 Part 2. The symbol for the tolerance of the IS0 metric trape- zoidal screw thread concerns only the pitch diameter tolerance, sin
8、ce only one tolerance is laid down each time for the minor diameter of the nut thread and the outside diameter of the bolt thread. Each symbol comprises a figure denoting the tolerance grade a letter indicating the tolerance position and consisting of a capital letter for nut threadsand a small lett
9、er for bolt threads. Example for nut thread: Tr40 X 7 - 7H Example for bolt thread: Tr40 X 7 - 7e A fit between threaded components is indicated by the symbol for the tolerance on the nut thread followed by an oblique strokefollowed in turn by the symbol for the tolerance on the bolt thread. Example
10、: Tr40 X 7 - 7H/7e Outside diameter of bolt thread 4 Minor diameter of bolt thread 789 Pitch diameter of nut thread 789 Pitch diameter of bolt thread 61) 7 8 9 1) This tolerance grade is needed only for calculating the pitch diameter tolerances Td2 of tolerance grades 7,8 and 9. 4 Tolerance position
11、s (basic allowances) The following tolerance positions are standardized: Bolt threads: c and e for the pitch diameter tolerance, and h in all cases for the tolerance on the outside and minor diameters, .e. the basic allowance for these last two diameters is always O. Nut threads: The basic allowance
12、 for the outside, pitch and minor diameters is always O, .e. only tolerance position H is standardized, Continued on pages 2 to 8 Explanations on page 8 Alleinverkauf der Normen durch euth Verlag GmbH. Berlin 30 und Kln 1 09.79 DIN 103 Teil 3 engl. Preisgr. 6 Vertr.-Nr. O1 06 Page 2 DIN 103 Part 3 P
13、 mm 13 2 3 4 5 6 7 8 9 10 12 14 16 18 20 22 24 28 32 36 44 40 C e Pm Clm - 140 - 67 -150 - 71 -170 - 85 -190 - 95 -212 -106 - 236 -116 - 250 - 125 - 265 -132 - 280 -140 - 300 -150 - 335 -170 - 355 -160 - 375 -190 -400 - 200 -425 -212 - 450 -224 -475 - 236 - 500 - 250 - 530 - 265 - 560 - 280 - 600 -
14、300 - 630 -315 75 90 100 112 118 132 150 50 75 112 125 140 150 200 224 250 280 236 265 300 335 355 400 450 150 224 335 375 425 450 600 670 750 850 5 Lengths of thread engagement The lengths of thread engagement are subdivided into the two groups N (normal) and L (long). Dimensions in mm Table 3. Len
15、gths of thread Nominal dia- meter of thread Pitch P Figure 1. Nut thread with tolerance position H 11 engagement N from I to )r 1 over to 11,2 over 56 11,2 22.4 45 90 180 15 19 28 15 19 28 15 2 3 -.,ia 5 6 10 8 11 24 32 24 32 43 53 85 36 63 75 85 1 O0 125 1 50 22,4 Y Tolerance position 3 5 6 36 : 1
16、63 25 75 C e IlII 45 Ao = Basic allowance (=upper allowance) for bolt thread Figure 2. Bolt thread with tolerance positions c and e at pitch diameter for pitch diameter tolerance and h for the tolerance on outside and minor diameter 7 8 10 12 3 4 8 45 56 118 1 5s 38 118 Table 2. Basic allowances A,
17、for pitch diameter of bolt thread I I 1 9 10 12 50“ 1 60 170 132 140 170 90 AO Tolerance position I Pitch 14 16 18 67 200 75 I 236 200 236 265 85 I 265 24 71 36 I 106 71 106 132 200 4 6 8 12 14 16 18 45 132 67 I 200 236 265 300 1 80 355 20 22 24 28 335 355 400 450 8 12 18 1 50 224 335 375 425 450 20
18、 22 24 32 36 40 44 600 670 750 850 DIN 103 Part 3 Page 3 Pitch P mm 13 2 3 4 5 6 7 8 9 10 12 14 6 Outside and minor diameter tolerances 6.1 Minor diameter tolerances TD for nut thread Td Tolerance grade 4 Pm 150 180 236 300 335 375 425 450 500 530 600 670 Table 4. Pitch P mm 13 2 3 4 5 6 7 8 9 10 12
19、 14 16 18 20 22 24 28 32 36 40 44 I TDl Tolerance grade 4 Pm 1 90 236 315 375 450 500 560 630 670 710 800 900 1 O00 1120 1180 1250 1320 1500 1600 1800 1 900 2000 16 18 20 22 24 28 710 800 850 900 950 1 O60 1 1400 Page 4 DIN 103 Part 3 Pitch P 6.4 Minor diameter tolerances Td3 for bolt thread Toleran
20、ce position c of pitch diameter tolerance Tolerance grade Table 6. 1.5 2 3 2 3 4 5 8 3 5 6 7 8 10 12 3 4 8 9 10 12 14 16 18 4 6 8 12 14 16 18 20 22 24 28 8 12 18 20 22 24 32 36 40 44 Tolerance position e of pitch diameter tolerance Tolerance grade 352 388 435 400 450 52 1 562 709 482 587 655 694 734
21、 800 866 50 1 565 765 81 1 83 1 929 970 1038 1100 584 705 796 960 1018 1075 1150 1175 1232 1313 1388 828 998 1187 1263 1 288 1363 1530 1623 1663 1755 No mina I diameter of thread d to mrn over mm 7 Iim 8 IJJn 7 mm 405 445 501 398 446 504 332 366 416 383 435 514 279 309 350 32 1 365 426 47 1 525 589
22、544 61 4 690 775 965 5.6 11,2 465 529 595 462 520 609 656 828 11,2 22,4 45 456 576 550 695 669 832 564 681 767 670 806 899 397 537 481 479 575 649 585 700 781 22,4 81 3 859 925 998 950 1015 1087 1223 569 601 650 69 1 688 726 775 823 825 882 937 1048 589 659 890 70 1 784 1052 41 6 470 632 504 564 757
23、 61 6 689 91 9 943 963 1085 1118 1138 1273 67 1 681 754 803 813 910 978 988 1098 1180 1253 1320 720 868 970 1160 1243 1315 1388 45 90 180 1142 1213 1288 690 830 928 1122 1355 1438 1525 81 5 986 1103 1335 1418 1500 1588 805 853 900 489 587 663 785 843 890 950 967 1028 1088 595 712 795 947 1018 1078 1
24、138 1193 1263 1338 90 1363 1450 1538 1625 1613 1700 1800 1900 962 101 1 1074 1138 1150 1224 1299 1375 1400 1474 1561 1 650 1020 1223 1450 965 1173 1400 1488 1513 1600 1153 1398 1650 1750 1775 1875 832 998 1 200 1275 1287 1361 695 823 987 1050 1062 1124 1537 1549 1636 1827 1 930 1950 2065 355 1 80 17
25、80 1885 1925 2030 2092 221 o 2250 2380 1265 1343 1 363 1440 1515 1605 1625 1715 DIN 103 Part 3 Page 5 Pitch P mm 1,s 2 3 2 3 4 5 8 7 Pitch diameter tolerances 7.1 Pitch diameter tolerances TD2 for nut thread Table 7. TD2 Tolerance grade 7 8 9 l.rm Pm Pm 224 280 355 250 31 5 400 280 355 450 265 335 4
26、25 300 375 475 355 450 560 375 475 600 475 600 750 Nominal diameter of thread d 7 8 10 12 3 4 8 9 10 12 14 16 18 4 6 8 12 over mm 475 600 750 500 630 800 530 670 850 560 710 900 355 450 560 400 500 630 530 670 850 560 710 900 560 710 900 630 800 1 O00 670 850 1060 710 900 1120 750 950 1180 425 530 6
27、70 500 630 800 560 710 900 670 850 1060 11,2 20 22 24 28 8 12 18 20 22 24 32 36 40 44 22.4 800 1 O00 1250 850 1060 1320 900 1120 1400 950 1180 1500 600 750 950 710 900 1120 850 1060 1320 900 1120 1400 900 1120 1400 950 1180 1500 1 o60 1320 1700 1120 1400 1800 1120 1400 1800 1250 1500 1900 45 90 180
28、to mm 11.2 22,4 45 90 180 355 3 5 6 425 500 1 560 530 630 710 14 16 18 710 750 1 800 950 1 1 O00 1120 1180 1250 Page 6 DIN 103 Part 3 7.2 Pitch diameter tolerances Td2 for bolt thread Table 8. I I I 1 5 8 3 5 6 7 8 10 12 3 4 8 9 10 12 14 16 18 224 280 355 450 280 355 450 560 200 250 31 5 400 236 300
29、 375 475 265 335 425 530 280 355 450 560 300 375 475 600 31 5 400 500 630 335 425 530 710 21 2 265 335 425 236 300 375 475 31 5 400 500 630 335 425 530 670 335 425 530 670 375 475 600 750 400 500 630 800 425 530 670 850 450 560 710 900 20 22 24 28 - 475 600 750 950 500 630 800 1 O00 530 670 850 1060
30、 560 710 900 1120 Td2 Tolerance grade Pitch P Nominal diameter of thread d over mm to mm 13 2 3 132 150 170 170 212 265 190 212 11,2 22.4 56 11.2 2 1 60 3 180 4 I 212 250 1 280 265 335 31 5 355 400 22,4 45 45 90 90 4 6 8 12 250 300 335 400 425 450 475 31 5 375 425 500 530 560 600 500 600 670 800 850
31、 900 950 400 475 530 630 670 710 750 14 16 18 180 8 12 18 355 425 500 450 530 630 710 850 1 O00 1 o60 1 o60 1120 1250 1320 1320 1400 670 670 710 20 22 24 32 36 40 44 530 530 560 630 670 670 710 180 355 900 1 O00 1060 1060 1120 800 850 850 900 DIN 103 Part 3 Page 7 Multiple of Td2 Of quality 6 1.7 8
32、Recommended tolerance fields To reduce the number of gauges and tools, only the tolerance fields indicated in Tables 9 and 10 should be selected. If the length of engagement is not known, engagement group N is recommended. Threading tools and gauges should always be marked with the tolerance field i
33、n order to prevent any confusion or mistakes involving tools of the old type used so far. In particular, overlapping of pilots on taps is likely to arise. 8.1 Tolerance fields for pitch diameter of nut thread Table 9 2.12 2.65 Tolerance grade med iu m coarse Tolerance f ields for pitch diameter Enga
34、gement groups N L 7H 8H 8H 9H . 8.4 Tolerance f ield for outside diameter of bolt thread The only tolerance field laid down for the outside dia- meter of the bolt thread is 4h. Tolerance grade medium coarse 9 Formulae 9.1 Lengths of engagement The lengths of engagement are calculated according to Ta
35、ble 11. Tolerance fields for pitch diameter Engagement groups N L 7e 8e 8c 9c Table 11. Engagement groups Lengths of engagement 1 Tolerance quality Multiple of Td2 of quality 6 2.24 P * dO.2 to 6.7 P dO.2 over 6.7 P. do.2 nominal diameter series according to Table 3. 789 1.25 1.6 2 9.2 Tolerances TD
36、 The pitch diameter tolerances TD2 are obtained by multiplying the pitch diameter tolerances for bolt threads Td2 of tolerance grade 6 by the factors shown in Table 12. Table 12. I Tolerance quality 171 81 91 9.3 Tolerances TD The minor diameter tolerances TD1 of grade 4 are calculated by means of t
37、he formula below: TD1 = 0.63 (230 * PO.) TD1 in pm, P in mm. 9.4 Tolerances Td The outside diameter tolerances Td of grade 4 are calculated by means of the formula below: Td = 0.63 (180 - y) Td in pm, P in mm. 9.5 Tolerances Td2 The pitch diameter tolerances Td2 of grade 6 are calculated by means of
38、 the formula below: Td2 = 9Op.4 . doa Td2 in pm, P and d in mm wherein d is the geometric mean of the nominal dia- meter range. The pitch diameter tolerances T,-Q for other tolerance grades are obtained by multiplying the pitch diameter tolerances for bolt threads of tolerance grade 6 by the factors
39、 shown in Table 13: 9.6 Tolerances Td3 The minor diameter tolerances Td3 are calculated by means of the formula below: A, (absolute value), Td2 and Td3 in pm. Td3 = (1.25 Td2) +A, 9.7 Basic allowance A, A, (for tolerance position e and up to P = 6 mm) A, (for tolerance osition e and for P = 7 to 44
40、mm) A, (for tolerance position c and up to P = 2 mm) A, (for tolerance position c and for P = 3 to 44 mm) The values laid down in Table 2 are empirical. They differ from those calculated by means of the above formulae by not more than 3%. = -(50+11 P) pm =-47.48 IP P =-(125+11 P) pm =-(5+94.12 Page
41、8 DIN 103 Part 3 9.8 Rounding rules The values for the outside, pitch and minor diameter tolerances have been calculated in accordance with the formulae indicated in the Sections above and then rounded to the nearest value of the preferred number series R40 according to DIN 323 Part 1. Excluded from
42、 such rounding are the tolerances Td3 for the minor diameter of the bolt thread. 10 Multiplestart trapezoidal screw thread In the case of multiplestart trapezoidal screw threads, the pitch P (axial distance between two adjacent equal-directed thread flanks) of the singlestart trape- zoidal thread ha
43、s been adopted as the basis for the basic allowances A, the minor diameter tolerances for the nut thread TD the outside diameter tolerances for the bolt thread Td. On the other hand, the pitch diameter tolerances for the nut thread TD2 and for the bolt thread T.2 of the multiple-start thread with le
44、ad Ph (axial displacement during one revolution) have been increased. The basis for determining these tolerances is the pitch diameter tolerance of the single-start trapezoidal thread with pitch P. These tolerances are multiplied by a factor related to the number of starts and taken from the preferr
45、ed number series R20 according to DIN 323 Part 1 in accordance with Table 14. Table 14. Number of starts (R 20) factor 1.12 1.25 When multiple-start threads are manufactured with large leads for which the tolerances TD2 and Td2 can no longer be taken from Tables 7 and 8, the values for TD2 and Td2 m
46、ust be calculated according to the formulae given in Sections 9.2 and 9.5. Further standards DIN 103 Part 1 DIN 103 Part 2 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; profiles IS0 metric trapezoidal screw thread; gene
47、ral plan IS0 metric trapezoidal screw thread; nominal dimensions IS0 metric trapezoidal screw thread; limiting sizesfor nut threads from 8 to 100 mm nominal diameter IS0 metric trapezoidal screw thread; limiting sizes for nut threads from 105 to 300 mm nominal diameter IS0 metric trapezoidal screw t
48、hread; limiting sizes for bolt threads from 8 to 100 mm nominal diameter IS0 metric trapezoidal screw thread; limiting sizes for bolt threadsfrom 105 to 300 mm nominal diameter (Preliminary Standard) IS0 metric trapezoidal screw thread; gauges for bolt and nut threads, gauge dimensions and construct
49、ion features Explanations This Standard contains a tolerance system for general purpose trapezoidal screw threads which is based on the The following restrictions have been introduced in comparison with the tolerances for the fastening thread : tolerance system for fastening threads according to DIN 13 Part 14 and Part 15, but which, in comparison with the tolerance system for fastening threads, has undergone a considerable restriction in numbers of tolerance grades, tolerance positions and engagement groups. The basic allowances for tolerance position c ha
