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Thread Pitch Chart
Thread pitch and TPI for every metric coarse, metric fine, UNC and UNF size, with pitch diameter, minor diameter and tensile stress area.
Pitch is the distance between adjacent threads (metric) or the count of threads per inch (imperial). Tensile stress area is the number that actually sets a bolt's strength — it is based on the mean of pitch and minor diameter, not the nominal size.
Metric coarse
| Thread | Pitch | TPI equiv. | Pitch dia. | Minor dia. | Stress area |
|---|
| M1.6×0.35 | 0.35 mm | 72.57 | 1.373 | 1.221 | 1.27 mm² |
| M2×0.4 | 0.4 mm | 63.5 | 1.74 | 1.567 | 2.07 mm² |
| M2.5×0.45 | 0.45 mm | 56.44 | 2.208 | 2.013 | 3.39 mm² |
| M3×0.5 | 0.5 mm | 50.8 | 2.675 | 2.459 | 5.03 mm² |
| M3.5×0.6 | 0.6 mm | 42.33 | 3.11 | 2.851 | 6.78 mm² |
| M4×0.7 | 0.7 mm | 36.29 | 3.545 | 3.242 | 8.78 mm² |
| M5×0.8 | 0.8 mm | 31.75 | 4.48 | 4.134 | 14.18 mm² |
| M6×1 | 1 mm | 25.4 | 5.351 | 4.918 | 20.12 mm² |
| M7×1 | 1 mm | 25.4 | 6.351 | 5.918 | 28.86 mm² |
| M8×1.25 | 1.25 mm | 20.32 | 7.188 | 6.647 | 36.61 mm² |
| M10×1.5 | 1.5 mm | 16.93 | 9.026 | 8.376 | 57.99 mm² |
| M12×1.75 | 1.75 mm | 14.51 | 10.863 | 10.106 | 84.27 mm² |
| M14×2 | 2 mm | 12.7 | 12.701 | 11.835 | 115.44 mm² |
| M16×2 | 2 mm | 12.7 | 14.701 | 13.835 | 156.67 mm² |
| M18×2.5 | 2.5 mm | 10.16 | 16.376 | 15.294 | 192.47 mm² |
| M20×2.5 | 2.5 mm | 10.16 | 18.376 | 17.294 | 244.79 mm² |
| M22×2.5 | 2.5 mm | 10.16 | 20.376 | 19.294 | 303.4 mm² |
| M24×3 | 3 mm | 8.47 | 22.052 | 20.753 | 352.5 mm² |
| M27×3 | 3 mm | 8.47 | 25.052 | 23.753 | 459.41 mm² |
| M30×3.5 | 3.5 mm | 7.26 | 27.727 | 26.211 | 560.59 mm² |
| M33×3.5 | 3.5 mm | 7.26 | 30.727 | 29.211 | 693.55 mm² |
| M36×4 | 4 mm | 6.35 | 33.402 | 31.67 | 816.72 mm² |
| M39×4 | 4 mm | 6.35 | 36.402 | 34.67 | 975.75 mm² |
| M42×4.5 | 4.5 mm | 5.64 | 39.077 | 37.129 | 1120.91 mm² |
| M45×4.5 | 4.5 mm | 5.64 | 42.077 | 40.129 | 1306.01 mm² |
| M48×5 | 5 mm | 5.08 | 44.752 | 42.587 | 1473.15 mm² |
| M52×5 | 5 mm | 5.08 | 48.752 | 46.587 | 1757.84 mm² |
| M56×5.5 | 5.5 mm | 4.62 | 52.428 | 50.046 | 2030.02 mm² |
| M60×5.5 | 5.5 mm | 4.62 | 56.428 | 54.046 | 2362.02 mm² |
| M64×6 | 6 mm | 4.23 | 60.103 | 57.505 | 2675.98 mm² |
Metric fine
| Thread | Pitch | TPI equiv. | Pitch dia. | Minor dia. | Stress area |
|---|
| M3×0.35 | 0.35 mm | 72.57 | 2.773 | 2.621 | 5.61 mm² |
| M4×0.5 | 0.5 mm | 50.8 | 3.675 | 3.459 | 9.79 mm² |
| M5×0.5 | 0.5 mm | 50.8 | 4.675 | 4.459 | 16.12 mm² |
| M6×0.75 | 0.75 mm | 33.87 | 5.513 | 5.188 | 22.03 mm² |
| M8×1 | 1 mm | 25.4 | 7.351 | 6.918 | 39.17 mm² |
| M8×0.75 | 0.75 mm | 33.87 | 7.513 | 7.188 | 41.81 mm² |
| M10×1.25 | 1.25 mm | 20.32 | 9.188 | 8.647 | 61.2 mm² |
| M10×1 | 1 mm | 25.4 | 9.351 | 8.918 | 64.49 mm² |
| M12×1.5 | 1.5 mm | 16.93 | 11.026 | 10.376 | 88.13 mm² |
| M12×1.25 | 1.25 mm | 20.32 | 11.188 | 10.647 | 92.07 mm² |
| M14×1.5 | 1.5 mm | 16.93 | 13.026 | 12.376 | 124.55 mm² |
| M16×1.5 | 1.5 mm | 16.93 | 15.026 | 14.376 | 167.25 mm² |
| M18×1.5 | 1.5 mm | 16.93 | 17.026 | 16.376 | 216.23 mm² |
| M20×1.5 | 1.5 mm | 16.93 | 19.026 | 18.376 | 271.5 mm² |
| M22×1.5 | 1.5 mm | 16.93 | 21.026 | 20.376 | 333.06 mm² |
| M24×2 | 2 mm | 12.7 | 22.701 | 21.835 | 384.42 mm² |
| M27×2 | 2 mm | 12.7 | 25.701 | 24.835 | 495.74 mm² |
| M30×2 | 2 mm | 12.7 | 28.701 | 27.835 | 621.2 mm² |
| M33×2 | 2 mm | 12.7 | 31.701 | 30.835 | 760.8 mm² |
| M36×3 | 3 mm | 8.47 | 34.051 | 32.752 | 864.94 mm² |
| M39×3 | 3 mm | 8.47 | 37.051 | 35.752 | 1028.39 mm² |
| M42×3 | 3 mm | 8.47 | 40.051 | 38.752 | 1205.98 mm² |
| M45×3 | 3 mm | 8.47 | 43.051 | 41.752 | 1397.7 mm² |
| M48×3 | 3 mm | 8.47 | 46.051 | 44.752 | 1603.57 mm² |
| M52×3 | 3 mm | 8.47 | 50.051 | 48.752 | 1900.04 mm² |
| M56×4 | 4 mm | 6.35 | 53.402 | 51.67 | 2143.96 mm² |
| M60×4 | 4 mm | 6.35 | 57.402 | 55.67 | 2484.81 mm² |
| M64×4 | 4 mm | 6.35 | 61.402 | 59.67 | 2850.79 mm² |
Unified coarse (UNC)
Unified fine (UNF)