International Standards

Metric External Thread Chart

Metric threads, whether external or internal, are widely used on CNC machined parts. Threads play an important role in assembly, mating, and functional adjustment. Our CNC machining services can provide you with parts with precisely manufactured threads, which are inspected with thread gauges to ensure quality.

General Note: All dimensions are in millimeters.

Metric External Thread Chart

Thread Designation x Pitch

Tolerance
Class

 Major Dia. Pitch Dia. Minor Dia.
max. min. max. min. max. min.
M1.6 x 0.35 6g 1.581 1.496 1.354 1.291 1.202 1.075
M2 x 0.25 6g 1.982 1.915 1.820 1.764 1.711 1.610
M2 x 0.4 6g 1.981 1.886 1.721 1.654 1.548 1.408
M2.5 x 0.35 6g 2.481 2.396 2.254 2.191 2.102 1.998
M2.5 x 0.45 6g 2.480 2.380 2.188 2.117 1.993 1.840
M2.6 x 0.45 6g 2.580 2.480 2.288 2.217 2.093 1.940
M3 x 0.35 6g 2.981 2.896 2.754 2.687 2.602 2.471
M3 x 0.5 6g 2.980 2.874 2.655 2.580 2.438 2.272
M3.5 x 0.6 6g 3.479 3.354 3.089 3.004 2.829 2.634
M4 x 0.5 6g 3.980 3.874 3.655 3.580 3.439 3.272
M4 x 0.7 6g 3.978 3.838 3.523 3.433 3.220 3.002
M5 x 0.5 6g 4.980 4.874 4.655 4.580 4.439 4.272
M5 x 0.8 6g 4.976 4.826 4.456 4.361 4.110 3.868
M6 x 0.5 6g 5.980 5.874 5.655 5.570 5.439 5.262
M6 x 0.75 6g 5.978 5.838 5.491 5.391 5.166 4.929
M6 x 1 6g 5.974 5.794 5.324 5.212 4.891 4.596
M7 x 0.5 6g 6.980 6.874 6.655 6.570 6.439 6.262
M7 x 1 6g 6.974 6.794 6.324 6.212 5.891 5.596
M8 x 0.5 6g 7.980 7.874 7.655 7.570 7.439 7.262
M8 x 0.75 6g 7.978 7.838 7.491 7.391 7.166 6.929
M8 x 1 6g 7.974 7.794 7.324 7.212 6.891 6.596
M8 x 1.25 6g 7.972 7.760 7.160 7.042 6.619 6.272
M9 x 0.5 6g 8.980 8.874 8.655 8.570 8.439 8.262
M9 x 1 6g 8.972 8.794 8.324 8.212 7.891 7.596
M9 x 1.25 6g 8.972 8.760 8.160 8.042 7.619 7.272
M10 x 0.75 6g 9.978 9.838 9.491 9.391 9.166 8.929
M10 x 1 6g 9.974 9.794 9.324 9.212 8.891 8.596
M10 x 1.25 6g 9.972 9.760 9.160 9.042 8.619 8.272
M10 x 1.5 6g 9.968 9.732 8.994 8.862 8.344 7.938
M11 x 0.5 6g 10.980 10.874 10.655 10.570 10.439 10.262
M11 x 1 6g 10.974 10.794 10.324 10.212 9.891 9.596
M11 x 1.5 6g 10.968 10.732 9.994 9.862 9.344 8.938
M12 x 0.5 6g 11.980 11.874 11.655 11.565 11.439 11.257
M12 x 1 6g 11.974 11.794 11.324 11.206 10.891 10.590
M12 x 1.25 6g 11.972 11.760 11.160 11.028 10.619 10.258
M12 x 1.5 6g 11.968 11.732 10.994 10.854 10.344 9.930
M12 x 1.75 6g 11.966 11.701 10.829 10.679 10.071 9.601
M14 x 0.5 6g 13.980 13.874 13.655 13.565 13.439 13.257
M14 x 1.5 6g 13.968 13.732 12.994 12.854 12.344 11.930
M14 x 2 6g 13.962 13.682 12.663 12.503 11.797 11.271

Thread Designation x Pitch

Tolerance
Class

 Major Dia. Pitch Dia. Minor Dia.
max. min. max. min. max. min.
M15 x 1 6g 14.974 14.794 14.324 14.206 13.891 13.590
M16 x 0.5 6g 15.980 15.874 15.655 15.565 15.439 15.257
M16 x 1.5 6g 15.968 15.732 14.994 14.854 14.344 13.930
M16 x 2 6g 15.962 15.682 14.663 14.503 13.797 13.271
M17 x 1 6g 16.974 16.794 16.324 16.206 15.891 15.590
M18 x 1 6g 17.974 17.794 17.324 17.206 16.891 16.590
M18 x 1.5 6g 17.968 17.732 16.994 16.854 16.344 15.930
M20 x 1 6g 19.974 19.794 19.324 19.206 18.891 18.590
M20 x 1.5 6g 19.968 19.732 18.994 18.854 18.344 17.930
M20 x 2.5 6g 19.958 19.623 18.334 18.164 17.251 16.624
M22 x 1.5 6g 21.968 21.732 20.994 20.854 20.344 19.930
M22 x 2.5 6g 21.958 21.623 20.334 20.164 19.251 18.624
M24 x 2 6g 23.962 23.682 22.663 22.493 21.797 21.261
M24 x 3 6g 23.952 23.577 22.003 21.803 20.704 19.955
M25 x 1.5 6g 24.968 24.732 23.994 23.844 23.344 22.920
M27 x 2 6g 26.962 26.682 25.663 25.493 24.797 24.261
M27 x 3 6g 26.952 26.577 25.003 24.803 23.704 22.955
M30 x 1.5 6g 29.968 29.732 28.994 28.844 28.344 27.920
M30 x 2 6g 29.962 29.682 28.663 28.493 27.797 27.261
M30 x 3.5 6g 29.947 29.522 27.674 27.462 26.158 25.306
M32 x 2 6g 31.962 31.682 30.663 30.493 29.797 29.261
M33 x 2 6g 32.962 32.682 31.663 31.493 30.797 30.261
M35 x 1.5 6g 34.968 34.732 33.994 33.844 33.344 32.920
M36 x 2 6g 35.962 35.682 34.663 34.493 33.797 33.261
M36 x 4 6g 35.940 35.465 33.342 33.118 31.610 30.654
M39 x 2 6g 38.962 38.682 37.663 37.493 36.797 36.261
M40 x 1.5 6g 39.968 39.732 38.994 38.844 38.344 37.920
M42 x 2 6g 41.962 41.682 40.663 40.493 39.797 39.261
M42 x 4.5 6g 41.937 41.437 39.014 38.778 37.065 36.006
M45 x 1.5 6g 44.968 44.732 43.994 43.844 43.344 42.920
M48 x 2 6g 47.962 47.682 46.663 46.483 45.797 45.251
M48 x 5 6g 47.929 47.399 44.681 44.431 42.516 41.351
M50 x 1.5 6g 49.968 49.732 48.994 48.834 48.344 47.910
M55 x 1.5 6g 54.968 54.732 53.994 53.834 53.344 52.910
M56 x 2 6g 55.962 55.682 54.663 54.483 53.797 53.251
M56 x 5.5 6g 55.925 55.365 52.353 52.088 49.971 48.700
M60 x 1.5 6g 59.968 59.732 58.994 58.834 58.344 57.910

Metric Internal Thread Chart

An internal thread is usually manufactured by a thread tap or a thread cutter, depending on the size of the thread. To select the suitable thread cutting tool matters for different kinds of raw material or thread dimensions. You are welcome to contact us if you have any questions about CNC machining threads.

Metric Internal Thread Chart

Thread
Designation

Tolerance
Class

 Minor Dia., 
D1		 Pitch Dia., 
D2		 Major Dia.,
D
min. max. min. max. min. max.
M1.6 x 0.35 6H 1.221 1.321 1.373 1.458 1.600 1.736
M2 x 0.4 6H 1.567 1.679 1.740 1.830 2.000 2.148
M2.5 x 0.45 6H 2.013 2.138 2.208 2.303 2.500 2.660
M3 x 0.5 6H 2.459 2.599 2.675 2.775 3.000 3.172
M3.5 x 0.6 6H 2.850 3.010 3.110 3.222 3.500 3.698
M4 x 0.7 6H 3.242 3.422 3.545 3.663 4.000 4.219
M5 x 0.8 6H 4.134 4.334 4.480 4.605 5.000 5.240
M6 x 1 6H 4.917 5.153 5.350 5.500 6.000 6.294
M8 x 1.25 6H 6.647 6.912 7.188 7.348 8.000 8.340
M8 x 1 6H 6.917 7.153 7.350 7.500 8.000 8.294
M10 x 1.5 6H 8.376 8.676 9.026 9.206 10.000 10.397
M10 x 1.25 6H 8.647 8.912 9.188 9.348 10.000 10.340
M10 x 1 6H 8.917 9.153 9.350 9.500 10.000 10.294
M10 x 0.75 6H 9.188 9.378 9.513 9.645 10.000 10.240
M12 x 1.75 6H 10.106 10.441 10.863 11.063 12.000 12.452
M12 x 1.5 6H 10.376 10.676 11.026 11.216 12.000 12.407
M12 x 1.25 6H 10.647 10.912 11.188 11.368 12.000 12.360
M12 x 1 6H 10.917 11.153 11.350 11.510 12.000 12.304
M14 x 2 6H 11.835 12.210 12.701 12.913 14.000 14.501
M14 x 1.5 6H 12.376 12.676 13.026 13.216 14.000 14.407
M15 x 1 6H 13.917 14.153 14.350 14.510 15.000 15.304
M16 x 2 6H 13.835 14.210 14.701 14.913 16.000 16.501
M16 x 1.5 6H 14.376 14.676 15.026 15.216 16.000 16.407
M17 x 1 6H 15.917 16.153 16.350 16.510 17.000 17.304
M18 x 1.5 6H 16.376 16.676 17.026 17.216 18.000 18.407
M20 x 2.5 6H 17.294 17.744 18.376 18.600 20.000 20.585
M20 x 1.5 6H 18.376 18.676 19.026 19.216 20.000 20.407
M20 x 1 6H 18.917 19.153 19.350 19.510 20.000 20.304
M22 x 2.5 6H 19.294 19.744 20.376 20.600 22.000 22.585
M22 x 1.5 6H 20.376 20.676 21.026 21.216 22.000 22.407
M24 x 3 6H 20.752 21.252 22.051 22.316 24.000 24.698
M24 x 2 6H 21.835 22.210 22.701 22.925 24.000 24.513
M25 x 1.5 6H 23.376 23.676 24.026 24.226 25.000 25.417
M27 x 3 6H 23.752 24.252 25.051 25.316 27.000 27.698
M27 x 2 6H 24.835 25.210 25.701 25.925 27.000 27.513
M30 x 3.5 6H 26.211 26.771 27.727 28.007 30.000 30.786
M30 x 2 6H 27.835 28.210 28.701 28.925 30.000 30.513
M30 x 1.5 6H 28.376 28.676 29.026 29.226 30.000 30.417
M33 x 2 6H 30.835 31.210 31.701 31.925 33.000 33.513
M35 x 1.5 6H 33.376 33.676 34.026 34.226 35.000 35.417
M36 x 4 6H 31.670 32.270 33.402 33.702 36.000 36.877
M36 x 2 6H 33.835 34.210 34.701 34.925 36.000 36.513
M39 x 2 6H 36.835 37.210 37.701 37.925 39.000 39.513
M40 x 1.5 6H 38.376 38.676 39.026 39.226 40.000 40.417
M42 x 4.5 6H 37.129 37.799 39.077 39.392 42.000 42.964
M42 x 2 6H 39.835 40.21 40.701 40.925 42.000 42.513
M45 x 1.5 6H 43.376 43.676 44.026 44.226 45.000 45.417
M48 x 5 6H 42.587 43.297 44.752 45.087 48.000 49.056
M48 x 2 6H 45.835 46.210 46.701 46.937 48.000 48.525
M50 x 1.5 6H 48.376 48.676 49.026 49.238 50.000 50.429
M55 x 1.5 6H 53.376 53.676 54.026 54.238 55.000 55.429
M56 x 5.5 6H 50.046 50.796 52.428 52.783 56.000 57.149
M56 x 2 6H 53.835 54.210 54.701 54.937 56.000 56.525
M60 x 1.5 6H 58.376 58.676 59.026 59.238 60.000 60.429

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