ISO 724 - Metric Threads
ISO 724 specifies basic dimensions of metric threads in accordance with ISO 261. Dimensions refer to the basic profile in accordance with ISO 68.
The pitch varies from coarse to extra fine with up to 5 different pitches for some dimensions. The thread angle is 60o and the thread depth is 0.614 x pitch.
Metric Threads - Coarser Threads
The table below indicates some of the most used coarse threads up to size M 68. Note that the ISO 724 standard specifies threads up to M 300. The table below is not complete.
| Size - Nominal Diameter (mm) | Pitch1) (mm) | Clearance Drill (mm) | Tap Drill (mm) | Tensile Stress Area (mm2) |
|---|---|---|---|---|
| M 1.6 | 0.35 | 1.8 | 1.25 | |
| M 2 | 0.40 | 2.4 | 1.60 | |
| M 2.5 | 0.45 | 2.90 | 2.00 | |
| M 3 | 0.50 | 3.40 | 2.50 | |
| M 3.5 | 0.60 | 3.90 | 2.90 | |
| M 4 | 0.70 | 4.50 | 3.30 | 8.78 |
| M 5 | 0.80 | 5.50 | 4.20 | 14.2 |
| M 6 | 1.00 | 6.60 | 5.00 | 20.1 |
| M 8 | 1.25 | 9.00 | 6.80 | 36.6 |
| M 10 | 1.50 | 12.00 | 8.50 | 58.0 |
| M 12 | 1.75 | 14.00 | 10.20 | 84.3 |
| M 14 | 2.00 | 16.00 | 12.00 | |
| M 16 | 2.00 | 18.00 | 14.00 | 157 |
| M 20 | 2.50 | 22.00 | 17.50 | 245 |
| M 22 | 2.50 | 25.00 | 19.50 | |
| M 24 | 3.00 | 27.00 | 21.00 | 353 |
| M 27 | 3.00 | 30.00 | 24.00 | |
| M 30 | 3.50 | 33.00 | 26.50 | 561 |
| M 36 | 4.00 | 40.00 | 32.00 | 817 |
| M 42 | 4.50 | 46.00 | 37.50 | 1120 |
| M 48 | 5.00 | 53.00 | 43.00 | 1470 |
| M 56 | 5.50 | 62.00 | 50.50 | 2030 |
| M 64 | 6.00 | 70.00 | 58.00 | 2680 |
| M 68 | 6.00 | 74.00 | 62.00 |
1) For metric threads pitch is the distance between threads.
- 1 mm = 0.039 inches
Download and print metric coarce threads clearance and tap drill chart
Metric Threads - Finer Threads
It is common to designate metric fine threads with the capital M plus an indication to their nominal outer diameter and their pitch:
M size x pitch
Example:
M 10 x 1.5
The table below indicates the typically used finer threads up to size M 100. Note that the ISO 724 standard specifies threads up to M 300.
| Size - Nominal Diameter | Pitch1) (mm) | Tap Drill (mm) | Tensile Stress Area (mm2) |
|---|---|---|---|
| M 1.0 x 0.2 | 0.20 | 0.80 | |
| M 1.1 x 0.2 | 0.20 | 0.90 | |
| M 1.2 x 0.2 | 0.20 | 1.00 | |
| M 1.4 x 0.2 | 0.20 | 1.20 | |
| M 1.6 x 0.2 | 0.20 | 1.40 | |
| M 1.8 x 0.2 | 0.20 | 1.60 | |
| M 2 x 0.25 | 0.25 | 1.75 | |
| M 2.2 x 0.25 | 0.25 | 1.95 | |
| M 2.5 x 0.35 | 0.35 | 2.10 | |
| M 3 x 0.35 | 0.35 | 2.60 | |
| M 3.5 x 0.35 | 0.35 | 3.10 | |
| M 4 x 0.5 | 0.50 | 3.50 | |
| M 4.5 x 0.5 | 0.50 | 4.00 | |
| M 5 x 0.5 | 0.50 | 4.50 | |
| M 5.5 x 0.5 | 0.50 | 5.00 | |
| M 6 x 0.75 | 0.75 | 5.20 | 20.1 |
| M 7 x 0.75 | 0.75 | 6.20 | |
| M 8 x 0.75 | 0.75 | 7.20 | |
| M 8 x 1.0 | 1.00 | 7.00 | 39.2 |
| M 9 x 0.75 | 0.75 | 8.20 | |
| M 9 x 1 | 1.00 | 8.00 | |
| M 10 x 0.75 | 0.75 | 9.20 | |
| M 10 x 1 | 1.00 | 9.00 | 64.5 |
| M 10 x 1.25 | 1.25 | 8.80 | 61.2 |
| M 11 x 0.75 | 0.75 | 10.20 | |
| M 11 x 1 | 1.00 | 10.00 | |
| M 12 x 1 | 1.00 | 11.00 | |
| M 12 x 1.25 | 1.25 | 10.80 | 92.1 |
| M 12 x 1.5 | 1.50 | 10.50 | 88.1 |
| M 14 x 1.0 | 1.00 | 13.00 | |
| M 14 x 1.25 | 1.25 | 12.80 | |
| M 14 x 1.5 | 1.50 | 12.50 | |
| M 15 x 1 | 1.00 | 14.00 | |
| M 15 x 1.5 | 1.50 | 13.50 | |
| M 16 x 1 | 1.00 | 15.00 | 178 |
| M 16 x 1.5 | 1.50 | 14.50 | 167 |
| M 17 x 1.0 | 1.00 | 16.00 | |
| M 17 x 1.5 | 1.50 | 15.50 | |
| M 18 x 1.0 | 1.00 | 17.00 | |
| M 18 x 1.5 | 1.50 | 16.50 | |
| M 18 x 2.0 | 2.00 | 16.00 | |
| M 20 x 1.0 | 1.00 | 19.00 | |
| M 20 x 1.5 | 1.50 | 18.50 | 272 |
| M 20 x 2.0 | 2.00 | 18.00 | 258 |
| M 22 x 1.0 | 1.00 | 21.00 | |
| M 22 x 1.5 | 1.50 | 20.50 | |
| M 22 x 2.0 | 2.00 | 20.00 | |
| M 24 x 1.0 | 1.00 | 23.00 | |
| M 24 x 1.5 | 1.50 | 22.50 | 401 |
| M 24 x 2.0 | 2.00 | 22.00 | 384 |
| M 25 x 1.0 | 1.00 | 24.00 | |
| M 25 x 1.5 | 1.50 | 23.50 | |
| M 25 x 2.0 | 2.00 | 23.00 | |
| M 27 x 1.0 | 1.00 | 26.00 | |
| M 27 x 1.5 | 1.50 | 25.50 | |
| M 27 x 2.0 | 2.00 | 25.00 | |
| M 28 x 1.0 | 1.00 | 27.00 | |
| M 28 x 1.5 | 1.50 | 26.50 | |
| M 28 x 2.0 | 2.00 | 26.00 | |
| M 30 x 1.0 | 1.00 | 29.00 | |
| M 30 x 1.5 | 1.50 | 28.50 | |
| M 30 x 2.0 | 2.00 | 28.00 | 621 |
| M 30 x 3.0 | 3.00 | 27.00 | 581 |
| M 32 x 1.5 | 1.50 | 30.50 | |
| M 32 x 2.0 | 2.00 | 30.00 | |
| M 33 x 1.5 | 1.50 | 31.50 | |
| M 33 x 2.0 | 2.00 | 31.00 | |
| M 33 x 3.0 | 3.00 | 30.00 | |
| M 35 x 1.5 | 1.50 | 33.50 | |
| M 35 x 2.0 | 2.00 | 33.00 | |
| M 36 x 1.5 | 1.50 | 34.50 | |
| M 36 x 2.0 | 2.00 | 34.00 | 915 |
| M 36 x 3.0 | 3.00 | 33.00 | 865 |
| M 39 x 1.5 | 1.50 | 37.50 | |
| M 39 x 2.0 | 2.00 | 37.00 | |
| M 39 x 3.0 | 3.00 | 36.00 | |
| M 40 x 1.5 | 1.50 | 38.50 | |
| M 40 x 2.0 | 2.00 | 38.00 | |
| M 40 x 3.0 | 3.00 | 37.00 | |
| M 42 x 1.5 | 1.50 | 40.50 | |
| M 42 x 2.0 | 2.00 | 40.00 | |
| M 42 x 3.0 | 3.00 | 39.00 | 1210 |
| M 42 x 4.0 | 4.00 | 38.00 | 1150 |
| M 45 x 1.5 | 1.50 | 43.50 | |
| M 45 x 2.0 | 2.00 | 43.00 | |
| M 45 x 3.0 | 3.00 | 42.00 | |
| M 45 x 4.0 | 4.00 | 41.00 | |
| M 48 x 1.5 | 1.50 | 46.50 | |
| M 48 x 2.0 | 2.00 | 46.00 | |
| M 48 x 3.0 | 3.00 | 45.00 | 1600 |
| M 48 x 4.0 | 4.00 | 44.00 | 1540 |
| M 50 x 1.5 | 1.50 | 48.50 | |
| M 50 x 2.0 | 2.00 | 48.00 | |
| M 50 x 3.0 | 3.00 | 47.00 | |
| M 52 x 1.5 | 1.50 | 50.50 | |
| M 52 x 2.0 | 2.00 | 50.00 | |
| M 52 x 3.0 | 3.00 | 49.00 | |
| M 52 x 4.0 | 4.00 | 48.00 | |
| M 55 x 1.5 | 1.50 | 53.50 | |
| M 55 x 2.0 | 2.00 | 53.00 | |
| M 55 x 3.0 | 3.00 | 52.00 | |
| M 55 x 4.0 | 4.00 | 51.00 | |
| M 56 x 1.5 | 1.50 | 54.50 | |
| M 56 x 2.0 | 2.00 | 54.00 | |
| M 56 x 3.0 | 3.00 | 53.00 | |
| M 56 x 4.0 | 4.00 | 52.00 | |
| M 58 x 1.5 | 1.50 | 56.50 | |
| M 58 x 2.0 | 2.00 | 56.00 | |
| M 58 x 3.0 | 3.00 | 55.00 | |
| M 58 x 4.0 | 4.00 | 54.00 | |
| M 60 x 1.5 | 1.50 | 58.50 | |
| M 60 x 2.0 | 2.00 | 58.00 | |
| M 60 x 3.0 | 3.00 | 57.00 | |
| M 60 x 4.0 | 4.00 | 56.00 | |
| M 62 x 1.5 | 1.50 | 60.50 | |
| M 62 x 2.0 | 2.00 | 60.00 | |
| M 62 x 3.0 | 3.00 | 59.00 | |
| M 62 x 4.0 | 4.00 | 58.00 | |
| M 64 x 1.5 | 1.50 | 62.50 | |
| M 64 x 2.0 | 2.00 | 62.00 | |
| M 64 x 3.0 | 3.00 | 61.00 | |
| M 64 x 4.0 | 4.00 | 60.00 | |
| M 65 x 1.5 | 1.50 | 63.50 | |
| M 65 x 2.0 | 2.00 | 63.00 | |
| M 65 x 3.0 | 3.00 | 62.00 | |
| M 65 x 4.0 | 4.00 | 61.00 | |
| M 68 x 1.5 | 1.50 | 66.50 | |
| M 68 x 2.0 | 2.00 | 66.00 | |
| M 68 x 3.0 | 3.00 | 65.00 | |
| M 68 x 4.0 | 4.00 | 64.00 | |
| M 70 x 1.5 | 1.50 | 68.50 | |
| M 70 x 2.0 | 2.00 | 68.00 | |
| M 70 x 3.0 | 3.00 | 67.00 | |
| M 70 x 4.0 | 4.00 | 66.00 | |
| M 70 x 6.0 | 6.00 | 64.00 | |
| M 72 x 1.5 | 1.50 | 70.50 | |
| M 72 x 2.0 | 2.00 | 70.00 | |
| M 72 x 3.0 | 3.00 | 69.00 | |
| M 72 x 4.0 | 4.00 | 68.00 | |
| M 72 x 6.0 | 6.00 | 66.00 | |
| M 75 x 1.5 | 1.50 | 73.50 | |
| M 75 x 2.0 | 2.00 | 73.00 | |
| M 75 x 3.0 | 3.00 | 72.00 | |
| M 75 x 4.0 | 4.00 | 71.00 | |
| M 75 x 6.0 | 6.00 | 69.00 | |
| M 76 x 1.5 | 1.50 | 74.50 | |
| M 76 x 2.0 | 2.00 | 74.00 | |
| M 76 x 3.0 | 3.00 | 73.00 | |
| M 76 x 4.0 | 4.00 | 72.00 | |
| M 76 x 6.0 | 6.00 | 70.00 | |
| M 80 x 1.5 | 1.50 | 78.50 | |
| M 80 x 2.0 | 2.00 | 78.00 | |
| M 80 x 3.0 | 3.00 | 77.00 | |
| M 80 x 4.0 | 4.00 | 76.00 | |
| M 80 x 6.0 | 6.00 | 74.00 | |
| M 85 x 2.0 | 2.00 | 83.00 | |
| M 85 x 3.0 | 3.00 | 82.00 | |
| M 85 x 4.0 | 4.00 | 81.00 | |
| M 85 x 6.0 | 6.00 | 79.00 | |
| M 90 x 2.0 | 2.00 | 88.00 | |
| M 90 x 3.0 | 3.00 | 87.00 | |
| M 90 x 4.0 | 4.00 | 86.00 | |
| M 90 x 6.0 | 6.00 | 84.00 | |
| M 95 x 2.0 | 2.00 | 93.00 | |
| M 95 x 3.0 | 3.00 | 92.00 | |
| M 95 x 4.0 | 4.00 | 91.00 | |
| M 95 x 6.0 | 6.00 | 89.00 | |
| M 100 x 2.0 | 2.00 | 98.00 | |
| M 100 x 3.0 | 3.00 | 97.00 | |
| M 100 x 4.0 | 4.00 | 96.00 | |
| M 100 x 6.0 | 6.00 | 94.00 |
Related ISO Standards
- ISO 68:1973 ISO general purpose screw threads - Basic profile
- ISO 261:1973 ISO general purpose metric screw threads - General plan
- ISO 262:1973 ISO general purpose metric screw threads - Selected sizes for screws, bolts and nuts
- ISO 724:1993 ISO general-purpose metric screw threads - Basic dimensions
- ISO 965-1:1980 ISO general purpose metric screw threads - Tolerances - Part 1: Principles and basic data
- ISO 965-2:1980 ISO general purpose metric screw threads - Tolerances - Part 2: Limits of sizes for general purpose bolt and nut threads - Medium quality
- ISO 965-3:1980 ISO general purpose metric screw threads - Tolerances - Part 3: Deviations for constructional threads
- ISO 1502:1996 ISO general-purpose metric screw threads - Gauges and gauging
Threads produced to this standard are interchangeable with threads produced to the metric standard ANSI/ASME B1.13M Metric Screw Threads: M Profile.
Related Topics
• Miscellaneous
Engineering related topics like Beaufort Wind Scale, CE-marking, drawing standards and more.
• Threads
Thread data - metric, unified, ACME and others.
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