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Date Published:Jun. 18. 2015

ISO General Purpose Metric Screw Threads

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ISO General Purpose Metric Screw Threads

Basic profile, formula and basic dimensions of metric threads

en_11_technical-11-iso-general-purpose-metric-screw-threads-part-1-basic-profile
11_technical-11-iso-general-purpose-metric-screw-threads-part-1-basic-profile-2
Unit : mm
Nominal diameter*= 
Male screw outside diameter d,
female screw root diameter D 
Pitch P Height of engagement H₁  Effective diameters  
D₂/d₂
Female screw inside diameter D
Male screw root diameterd₁
Field 1 Field 2  Field 3 
Choice 1 Choice 2 Choice 3
1 - - 0.25 0.135 0.838 0.729
0.2 0.108 0.870 0.783
- 1.1 - 0.25 0.135 0.938 0.829
0.2 0.108 0.970 0.883
1.2 - - 0.25 0.135 1.038 0.929
0.2 0.108 1.070 0.983
- 1.4 - 0.3 0.162 1.205 1.075
0.2 0.108 1.270 1.183
1.6 - - 0.35 0.189 1.373 1.221
0.2 0.108 1.470 1.383
- 1.8 - 0.35 0.189 1.573 1.421
0.2 0.108 1.670 1.583
2 - - 0.4 0.217 1.740 1.567
0.25 0.135 1.838 1.729
- 2.2 - 0.45 0.244 1.908 1.713
0.25 0.135 2.038 1.929
2.5 - - 0.45 0.244 2.208 2.013
0.35 0.189 2.273 2.121
3 - - 0.5 0.271 2.675 2.459
0.35 0.189 2.773 2.621
- 3.5 - 0.6 0.325 3.110 2.850
0.35 0.189 3.273 3.121
4 - - 0.7 0.379 3.545 3.242
0.5 0.271 3.675 3.459
- 4.5 - 0.75 0.406 4.013 3.688
0.5 0.271 4.175 3.959
5 - - 0.8 0.433 4.480 4.134
0.5 0.271 4.675 4.459
- - 5.5 0.5 0.271 5.175 4.959
6 - - 1 0.541 5.350 4.917
0.75 0.406 5.513 5.188
- 7 -

1

0.541 6.350 5.917
0.75 0.406 6.513 6.188
8 - - 1.25 0.677 7.188 6.647
1 0.541 7.350 6.917
0.75 0.406 7.513 7.188
- - 9 1.25 0.677 8.188 7.647
1 0.541 8.350 7.917
0.75 0.406 8.513 8.188
10 - - 1.5 0.812 9.026 8.376
1.25 0.677 9.188 8.647
1 0.541 9.350 8.917
0.75 0.406 9.513 9.188
- - 11 1.5 0.812 10.026 9.376
1 0.541 10.350 9.917
0.75 0.406 10.513 10.188
12 - - 1.75 0.947 10.863 10.106
1.5 0.812 11.026 10.376
1.25 0.677 11.188 10.647
1 0.541 11.350 10.917
- 14 - 2 1.083 12.701 11.835
1.5 0.812 13.026 12.376
1.25 0.677 13.188 12.647
1 0.541 13.350 12.917
- - 15 1.5 0.812 14.026 13.376
 1 0.541 14.350 13.917
16 - - 2 1.083 14.701 13.835
1.5 0.812 15.026 14.376
1 0.541 15.350 14.917
- - 17 15 0.812 16.026 15.376
1 0.541 16.350 15.917
- 18 - 2.5 1.353 16.376 15.294
2 1.083 16.701 15.835
1.5 0.812 17.026 16.376
1 0.541 17.350 16.917
20 - - 2.5 1.353 18.376 17.294
2 1.083 18.701 17.835
1.5 0.812 19.026 18.376
1 0.541 19.350 18.917
- 22 - 2.5 1.353 20.376 19.294
2 1.083 20.701 19.835
1.5 0.812 21.026 20.376
1 0.541 21.350 20.917
24 - - 3 1.624 22.051 20.752
2 1.083 22.701 21.835
1.5 0.812 23.026 22.376
1 0.541 23.350 22.917
- - 25 2 1.083 23.701 22.835
1.5 0.812 24.026 23.376
1 0.541 24.350 23.917
- - 26 1.5 0.812 25.026 24.376
- 27 - 3 1.624 25.051 23.752
2 1.083 25.701 24.835
1.5 0.812 26.026 25.376
1 0.541 26.350 25.917
- - 28 2 1.083 26.701 25.835
1.5 0.812 27.026 26.376
1 0.541 27.350 26.917
30 - - 3.5 1.894 27.727 26.211
3 1.624 28.051 26.752
2 1.083 28.701 27.835
1.5 0.812 29.026 28.376
1 0.541 29.350 28.917
- - 32 2 1.083 30.701 29.835
1.5 0.812 31.026 30.376
- 33 - 3.5 1.894 30.727 29.211
3 1.624 31.051 29.752
2 1.083 31.701 30.835
1.5 0.812 32.026 31.376
- - 35 1.5 0.812 34.026 33.376
36 - - 4 2.165 33.402 31.670
3 1.624 34.051 32.752
2 1.083 34.701 33.835
1.5 0.812 35.026 34.376
- - 38 1.5 0.812 37.026 36.376
- 39 - 4 2.165 36.402 34.670
3 1.624 37.051 35.752
2 1.083 37.701 36.835
1.5 0.812 38.026 37.376
- - 40 3 1.624 38.051 36.752
2 1.083 38.701 37.835
1.5 0.812 39.026 38.376
42 - - 4.5 2.436 39.077 37.129
4 2.165 39.402  37.670
3 1.624 40.051 38.752
2 1.083 40.701 39.835
1.5 0.812 41.026 40.376
- 45 - 4.5 2.436 42.077 40.129
4 2.165 42.402 40.670
3 1.624 43.051 41.752
2 1.083 43.701 42.835
1.5 0.812 44.026 43.376
48 - - 5 2.706 44.752 42.587
4 2.165 45.402 43.670
3 1.624 46.051 44.752
2 1.083 46.701 45.835
1.5 0.812 47.026 46.376
- - 50 3 1.624 48.051 46.752
2 1.083 48.701 47.835
1.5 0.812 49.026 48.376
- 52 - 5 2.706 48.752 46.587
4 2.165 49.402 47.670
3 1.624 50.051 48.752
2 1.083 50.701 49.835
1.5 0.812 51.026 50.376
- - 55 4 2.165 52.402 50.670
3 1.624 53.051 51.752
2 1.083 53.701 52.835
1.5 0.812 54.026 53.376

Prioritize Field 1 and, if needed, choose Field 2 and Field 3 in that order.



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