This page provides tables listing sizes of inch and metric bolts, nuts, and washers. For information on bolted joints, see our bolted joint analysis reference.
Contents
- Hardware Sizes: Unified Inch Screw Thread
- Hardware Sizes: Metric Screw Thread
Related Pages:
•Bolted Joint Analysis
•Bolt Pattern Force Distribution
•Bolted Joint Calculator
Hardware Sizes: Unified Inch Screw Thread
This section contains tables of sizes for inch thread hardware.
Bolt Thread Sizes
The following table of thread sizes for coarse and fine thread was adapted from ASME B1.1:
| Size | Nominal (Major) Diameter [in] | Coarse Thread (UNC) | Fine Thread (UNF) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Threads Per Inch | Tensile Stress Area [in2] | Minor Area [in2] | Threads Per Inch | Tensile Stress Area [in2] | Minor Area [in2] | ||||
| #0 | 0.0600 | --- | --- | --- | 80 | 0.00180 | 0.00151 | ||
| #2 | 0.0860 | 56 | 0.00370 | 0.00310 | 64 | 0.00394 | 0.00339 | ||
| #4 | 0.1120 | 40 | 0.00604 | 0.00496 | 48 | 0.00661 | 0.00566 | ||
| #5 | 0.1250 | 40 | 0.00796 | 0.00672 | 44 | 0.00830 | 0.00716 | ||
| #6 | 0.1380 | 32 | 0.00909 | 0.00745 | 40 | 0.01015 | 0.00874 | ||
| #8 | 0.1640 | 32 | 0.0140 | 0.01196 | 36 | 0.01474 | 0.01285 | ||
| #10 | 0.1900 | 24 | 0.0175 | 0.01450 | 32 | 0.0200 | 0.0175 | ||
| 1/4" | 0.2500 | 20 | 0.0318 | 0.0269 | 28 | 0.0364 | 0.0326 | ||
| 5/16" | 0.3125 | 18 | 0.0524 | 0.0454 | 24 | 0.0580 | 0.0524 | ||
| 3/8" | 0.3750 | 16 | 0.0775 | 0.0678 | 24 | 0.0878 | 0.0809 | ||
| 7/16" | 0.4375 | 14 | 0.1063 | 0.0933 | 20 | 0.1187 | 0.1090 | ||
| 1/2" | 0.5000 | 13 | 0.1419 | 0.1257 | 20 | 0.1599 | 0.1486 | ||
| 9/16" | 0.5625 | 12 | 0.182 | 0.162 | 18 | 0.203 | 0.189 | ||
| 5/8" | 0.6250 | 11 | 0.226 | 0.202 | 18 | 0.256 | 0.240 | ||
| 3/4" | 0.7500 | 10 | 0.334 | 0.302 | 16 | 0.373 | 0.351 | ||
| 7/8" | 0.8750 | 9 | 0.462 | 0.419 | 14 | 0.509 | 0.480 | ||
| 1" | 1.0000 | 8 | 0.606 | 0.551 | 12 | 0.663 | 0.625 | ||
| 1-1/8" | 1.1250 | 7 | 0.763 | 0.693 | 12 | 0.856 | 0.812 | ||
| 1-1/4" | 1.2500 | 7 | 0.969 | 0.890 | 12 | 1.073 | 1.024 | ||
| 1-3/8" | 1.3750 | 6 | 1.155 | 1.054 | 12 | 1.315 | 1.260 | ||
| 1-1/2" | 1.5000 | 6 | 1.405 | 1.294 | 12 | 1.581 | 1.521 | ||
| 1-3/4" | 1.7500 | 5 | 1.90 | 1.74 | --- | --- | --- | ||
| 2" | 2.0000 | 4.5 | 2.50 | 2.30 | --- | --- | --- | ||
Bolt Thread Dimensions
The following equations can be used to calculate dimensions for Unified Inch threads:
| Equation, US Units [in] | Source | |
|---|---|---|
| Minor Diameter | dm.ext = dnom − 1.299038/TPI | Machinery's Handbook |
| Pitch Diameter | dp.ext = dnom − 0.64951905/TPI | ASME B1.1, Section 10.1p |
| Nominal Area |  | |
| Tensile Stress Area | | ASME B1.1, Appendix B |
| Minor Area (Shear Area) | |
In the table above, dnom is nominal diameter in inches and TPI is threads per inch.
Minimum Clearance Hole Diameters
The following table of clearance holes was adapted from ASME B18.2.8. The minimum hole diameters are given.
| Bolt Size | Bolt Dia. [in] | Normal Fit [in] | Close Fit [in] | Loose Fit [in] |
|---|---|---|---|---|
| #0 | 0.0600 | 0.076 | 0.067 | 0.094 |
| #2 | 0.0860 | 0.102 | 0.094 | 0.116 |
| #4 | 0.1120 | 0.128 | 0.120 | 0.144 |
| #5 | 0.1250 | 0.156 | 0.141 | 0.172 |
| #6 | 0.1380 | 0.170 | 0.154 | 0.185 |
| #8 | 0.1640 | 0.196 | 0.180 | 0.213 |
| #10 | 0.1900 | 0.221 | 0.206 | 0.238 |
| 1/4" | 0.2500 | 0.281 | 0.266 | 0.297 |
| 5/16" | 0.3125 | 0.344 | 0.328 | 0.359 |
| 3/8" | 0.3750 | 0.406 | 0.391 | 0.422 |
| 7/16" | 0.4375 | 0.469 | 0.453 | 0.484 |
| 1/2" | 0.5000 | 0.562 | 0.531 | 0.609 |
| 5/8" | 0.6250 | 0.688 | 0.656 | 0.734 |
| 3/4" | 0.7500 | 0.812 | 0.781 | 0.906 |
| 7/8" | 0.8750 | 0.938 | 0.906 | 1.031 |
| 1" | 1.0000 | 1.094 | 1.031 | 1.156 |
| 1-1/8" | 1.1250 | 1.219 | 1.156 | 1.312 |
| 1-1/4" | 1.2500 | 1.344 | 1.281 | 1.438 |
| 1-3/8" | 1.3750 | 1.500 | 1.438 | 1.609 |
| 1-1/2" | 1.5000 | 1.625 | 1.562 | 1.734 |
Bolt Thread Length
Per ASME B18.2.1, the nominal thread length of inch-series bolts can be found by:
where L is the total bolt length and dnom is the nominal bolt diameter.
Hex Bolt Head Dimensions
The following table of hex bolt head dimensions was adapted from ASME B18.6.3, Table 29, "Dimensions of Plain (Unslotted) and Slotted Regular and Large Hex Head Screws." This table is used for smaller size hardware.
| Size | Nominal (Major) Diameter [in] | Width Across Flats | Head Height | ||
|---|---|---|---|---|---|
| Minimum [in] | Maximum [in] | Minimum [in] | Maximum [in] | ||
| #2 | 0.0860 | 0.120 | 0.125 | 0.040 | 0.050 |
| #4 | 0.1120 | 0.181 | 0.188 | 0.049 | 0.060 |
| #6 | 0.1380 | 0.244 | 0.250 | 0.080 | 0.093 |
| #8 | 0.1640 | 0.244 | 0.250 | 0.096 | 0.110 |
| #10 | 0.1900 | 0.305 | 0.312 | 0.105 | 0.120 |
| 1/4" | 0.2500 | 0.367 | 0.375 | 0.172 | 0.190 |
| 5/16" | 0.3125 | 0.489 | 0.500 | 0.208 | 0.230 |
| 3/8" | 0.3750 | 0.551 | 0.562 | 0.270 | 0.295 |
The following table of hex bolt head dimensions was adapted from ASME B18.2.1, Table 2, "Dimensions of Hex Bolts."
| Size | Nominal (Major) Diameter [in] | Width Across Flats | Head Height | ||
|---|---|---|---|---|---|
| Nominal [in] | Minimum [in] | Nominal [in] | Minimum [in] | ||
| 1/4" | 0.2500 | 7/16"(0.438) | 0.425 | 11/64" | 0.150 |
| 5/16" | 0.3125 | 1/2"(0.500) | 0.484 | 7/32" | 0.195 |
| 3/8" | 0.3750 | 9/16"(0.562) | 0.544 | 1/4" | 0.226 |
| 7/16" | 0.4375 | 5/8"(0.625) | 0.603 | 19/64" | 0.272 |
| 1/2" | 0.5000 | 3/4"(0.750) | 0.725 | 11/32" | 0.302 |
| 5/8" | 0.6250 | 15/16"(0.938) | 0.906 | 27/64" | 0.378 |
| 3/4" | 0.7500 | 1-1/8"(1.125) | 1.088 | 1/2" | 0.455 |
| 7/8" | 0.8750 | 1-5/16"(1.312) | 1.269 | 37/64" | 0.531 |
| 1" | 1.0000 | 1-1/2"(1.500) | 1.450 | 43/64" | 0.591 |
| 1-1/8" | 1.1250 | 1-11/16"(1.688) | 1.631 | 3/4" | 0.658 |
| 1-1/4" | 1.2500 | 1-7/8"(1.875) | 1.812 | 27/32" | 0.749 |
| 1-3/8" | 1.3750 | 2-1/16"(2.062) | 1.994 | 29/32" | 0.810 |
| 1-1/2" | 1.5000 | 2-1/4"(2.250) | 2.175 | 1" | 0.902 |
| 1-5/8" | 1.6250 | 2-7/16"(2.438) | 2.356 | 1-3/32" | 0.978 |
| 1-3/4" | 1.7500 | 2-5/8"(2.625) | 2.538 | 1-5/32" | 1.054 |
| 1-7/8" | 1.8750 | 2-13/16"(2.812) | 2.719 | 1-1/4" | 1.130 |
| 2" | 2.0000 | 3"(3.000) | 2.900 | 1-11/32" | 1.175 |
Hex Nut Dimensions
The following table of hex nut dimensions was adapted from ASME B18.2.2, Table 1-1, "Dimensions of Square and Hex Machine Screw Nuts." This table is used for smaller size hardware.
| Size | Nominal (Major) Diameter [in] | Width Across Flats | Thickness | ||
|---|---|---|---|---|---|
| Nominal [in] | Minimum [in] | Minimum [in] | Maximum [in] | ||
| #0 | 0.060 | 5/32"(0.156) | 0.150 | 0.043 | 0.050 |
| #2 | 0.086 | 3/16"(0.188) | 0.180 | 0.057 | 0.066 |
| #4 | 0.112 | 1/4"(0.250) | 0.241 | 0.087 | 0.098 |
| #6 | 0.138 | 5/16"(0.312) | 0.302 | 0.102 | 0.114 |
| #8 | 0.164 | 11/32"(0.344) | 0.332 | 0.117 | 0.130 |
| #10 | 0.190 | 3/8"(0.375) | 0.362 | 0.117 | 0.130 |
| 1/4" | 0.250 | 7/16"(0.438) | 0.423 | 0.178 | 0.193 |
| 5/16" | 0.312 | 9/16"(0.562) | 0.545 | 0.208 | 0.225 |
| 3/8" | 0.375 | 5/8"(0.625) | 0.607 | 0.239 | 0.257 |
The following table of hex nut dimensions was adapted from ASME B18.2.2, Table 4, "Dimensions of Hex Nuts and Hex Jam Nuts."
| Size | Nominal (Major) Diameter [in] | Width Across Flats | Thickness | ||
|---|---|---|---|---|---|
| Minimum [in] | Maximum [in] | Minimum [in] | Maximum [in] | ||
| 1/4" | 0.2500 | 0.428 | 0.438 | 0.212 | 0.226 |
| 5/16" | 0.3125 | 0.489 | 0.500 | 0.258 | 0.273 |
| 3/8" | 0.3750 | 0.551 | 0.563 | 0.320 | 0.337 |
| 7/16" | 0.4375 | 0.675 | 0.688 | 0.365 | 0.385 |
| 1/2" | 0.5000 | 0.736 | 0.750 | 0.427 | 0.448 |
| 9/16" | 0.5625 | 0.861 | 0.875 | 0.473 | 0.496 |
| 5/8" | 0.6250 | 0.922 | 0.938 | 0.535 | 0.559 |
| 3/4" | 0.7500 | 1.088 | 1.125 | 0.617 | 0.665 |
| 7/8" | 0.8750 | 1.269 | 1.312 | 0.724 | 0.776 |
| 1" | 1.0000 | 1.450 | 1.500 | 0.831 | 0.887 |
| 1-1/8" | 1.1250 | 1.631 | 1.688 | 0.939 | 0.999 |
| 1-1/4" | 1.2500 | 1.812 | 1.875 | 1.030 | 1.094 |
| 1-3/8" | 1.3750 | 1.994 | 2.062 | 1.138 | 1.206 |
| 1-1/2" | 1.5000 | 2.175 | 2.250 | 1.245 | 1.317 |
| 1-5/8" | 1.6250 | 2.350 | 2.430 | 1.364 | 1.416 |
| 1-3/4" | 1.7500 | 2.538 | 2.625 | 1.460 | 1.540 |
| 1-7/8" | 1.8750 | 2.722 | 2.813 | 1.567 | 1.651 |
| 2" | 2.0000 | 2.900 | 3.000 | 1.675 | 1.763 |
Internal Thread Dimensions
The following equations can be used to calculate internal thread dimensions for Unified Inch threads:
| Equation, US Units [in] | Source | |
|---|---|---|
| Minor Diameter | dm.int = dnom − 1.08253175/TPI | ASME B1.1, Section 10.1s |
| Pitch Diameter | dp.int = dnom − 0.64951905/TPI | ASME B1.1, Section 8.3 |
In the table above, dnom is nominal diameter in inches and TPI is threads per inch.
Flat Washer Dimensions
The following table of flat washer dimensions was adapted from ASME B18.21.1, Table 11 for Type A Plain Washers. Type A washers come in 2 series: Narrow and Wide.
| Size | Basic Dia. [in] | Series | Inner Dia, Basic [in] | Outer Dia, Basic [in] | Thickness, Basic [in] |
|---|---|---|---|---|---|
| #0 | 0.0600 | --- | 0.078 | 0.188 | 0.020 |
| #2 | 0.0860 | --- | 0.094 | 0.250 | 0.020 |
| #4 | 0.1120 | --- | 0.125 | 0.312 | 0.032 |
| #6 | 0.1380 | --- | 0.156 | 0.375 | 0.049 |
| #8 | 0.1640 | --- | 0.188 | 0.438 | 0.049 |
| #10 | 0.1900 | --- | 0.219 | 0.500 | 0.049 |
| 1/4" | 0.2500 | Narrow | 0.281 | 0.625 | 0.065 |
| 1/4" | 0.2500 | Wide | 0.312 | 0.734 | 0.065 |
| 5/16" | 0.3125 | Narrow | 0.344 | 0.688 | 0.065 |
| 5/16" | 0.3125 | Wide | 0.375 | 0.875 | 0.083 |
| 3/8" | 0.3750 | Narrow | 0.406 | 0.812 | 0.065 |
| 3/8" | 0.3750 | Wide | 0.438 | 1.000 | 0.083 |
| 7/16" | 0.4375 | Narrow | 0.469 | 0.922 | 0.065 |
| 7/16" | 0.4375 | Wide | 0.500 | 1.250 | 0.083 |
| 1/2" | 0.5000 | Narrow | 0.531 | 1.062 | 0.095 |
| 1/2" | 0.5000 | Wide | 0.562 | 1.375 | 0.109 |
| 9/16" | 0.5625 | Narrow | 0.594 | 1.156 | 0.095 |
| 9/16" | 0.5625 | Wide | 0.625 | 1.469 | 0.109 |
| 5/8" | 0.6250 | Narrow | 0.656 | 1.312 | 0.095 |
| 5/8" | 0.6250 | Wide | 0.688 | 1.750 | 0.134 |
| 3/4" | 0.7500 | Narrow | 0.812 | 1.469 | 0.134 |
| 3/4" | 0.7500 | Wide | 0.812 | 2.000 | 0.148 |
| 7/8" | 0.8750 | Narrow | 0.938 | 1.750 | 0.134 |
| 7/8" | 0.8750 | Wide | 0.938 | 2.250 | 0.165 |
| 1" | 1.0000 | Narrow | 1.062 | 2.000 | 0.134 |
| 1" | 1.0000 | Wide | 1.062 | 2.500 | 0.165 |
| 1-1/8" | 1.1250 | Narrow | 1.250 | 2.250 | 0.134 |
| 1-1/8" | 1.1250 | Wide | 1.250 | 2.750 | 0.165 |
| 1-1/4" | 1.2500 | Narrow | 1.375 | 2.500 | 0.165 |
| 1-1/4" | 1.2500 | Wide | 1.375 | 3.000 | 0.165 |
| 1-3/8" | 1.3750 | Narrow | 1.500 | 2.750 | 0.165 |
| 1-3/8" | 1.3750 | Wide | 1.500 | 3.250 | 0.180 |
| 1-1/2" | 1.5000 | Narrow | 1.625 | 3.000 | 0.165 |
| 1-1/2" | 1.5000 | Wide | 1.625 | 3.500 | 0.180 |
| 1-5/8" | 1.6250 | --- | 1.750 | 3.750 | 0.180 |
| 1-3/4" | 1.7500 | --- | 1.875 | 4.000 | 0.180 |
| 1-7/8" | 1.8750 | --- | 2.000 | 4.250 | 0.180 |
| 2" | 2.0000 | --- | 2.125 | 4.500 | 0.180 |
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Hardware Sizes: Metric Screw Thread
This section contains tables of sizes for metric thread hardware.
Bolt Thread Sizes
The following table of thread sizes for coarse and fine pitch thread was created using the standard sizes from ASME B1.13M. Coarse pitch threads are preferred and should be used whenever possible, as stated in ASME B1.13M. The thread equations given previously for tensile stress area and for minor area were used in constructing the table.
The thread size designation for metric thread is given as "M[dia]x[pitch]". For example, a thread with a nominal diameter of 6 mm and a pitch of 1 mm is designated as "M6x1."
| Nominal (Major) Diameter [mm] | Coarse Pitch | Fine Pitch | ||||||
|---|---|---|---|---|---|---|---|---|
| Pitch [mm] | Tensile Stress Area [mm2] | Minor Area [mm2] | Pitch [mm] | Tensile Stress Area [mm2] | Minor Area [mm2] | |||
| 1.6 | 0.35 | 1.270 | 1.076 | --- | --- | --- | ||
| 2 | 0.4 | 2.073 | 1.789 | --- | --- | --- | ||
| 2.5 | 0.45 | 3.391 | 2.980 | --- | --- | --- | ||
| 3 | 0.5 | 5.031 | 4.473 | --- | --- | --- | ||
| 3.5 | 0.6 | 6.775 | 6.000 | --- | --- | --- | ||
| 4 | 0.7 | 8.779 | 7.750 | --- | --- | --- | ||
| 5 | 0.8 | 14.18 | 12.68 | --- | --- | --- | ||
| 6 | 1 | 20.12 | 17.89 | --- | --- | --- | ||
| 8 | 1.25 | 36.61 | 32.84 | 1 | 39.17 | 36.03 | ||
| 10 | 1.5 | 57.99 | 52.29 | 1.25 | 61.20 | 56.30 | ||
| 12 | 1.75 | 84.27 | 76.25 | 1.25 | 92.07 | 86.04 | ||
| 14 | 2 | 115.4 | 104.7 | 1.5 | 124.5 | 116.1 | ||
| 16 | 2 | 156.7 | 144.1 | 1.5 | 167.2 | 157.5 | ||
| 20 | 2.5 | 244.8 | 225.2 | 1.5 | 271.5 | 259.0 | ||
| 24 | 3 | 352.5 | 324.3 | 2 | 384.4 | 364.6 | ||
| 30 | 3.5 | 560.6 | 519.0 | 2 | 621.2 | 596.0 | ||
| 36 | 4 | 816.7 | 759.3 | 2 | 914.5 | 883.8 | ||
| 42 | 4.5 | 1121 | 1045 | 2 | 1264 | 1228 | ||
| 48 | 5 | 1473 | 1377 | 2 | 1671 | 1629 | ||
| 56 | 5.5 | 2030 | 1905 | 2 | 2301 | 2252 | ||
| 64 | 6 | 2676 | 2520 | 2 | 3031 | 2975 | ||
| 72 | 6 | 3460 | 3282 | 2 | 3862 | 3799 | ||
| 80 | 6 | 4344 | 4144 | 1.5 | 4851 | 4798 | ||
| 90 | 6 | 5591 | 5364 | 2 | 6099 | 6020 | ||
| 100 | 6 | 6995 | 6740 | 2 | 7562 | 7473 | ||
| 110 | --- | --- | --- | 2 | 9182 | 9084 | ||
Bolt Thread Dimensions
The following equations can be used to calculate dimensions for ISO metric threads. The thread profile is based on a parameter H, the height of the fundamental triangle. The value of H is related to the thread pitch, P by:
| Equation, Metric Units [mm] | Source | |
|---|---|---|
| Minor Diameter | dm.ext = dnom − 1.226869·P | Shigley |
| Pitch Diameter | dp.ext = dnom − 0.75·H = dnom − 0.64951905·P | Machinery's Handbook |
| Nominal Area | | |
| Tensile Stress Area | | ASME B1.13M, Appendix B |
| Minor Area (Shear Area) | |
In the table above, dnom is nominal diameter in millimeters and P is the thread pitch in millimeters.
Minimum Clearance Hole Diameters
The following table of clearance holes was adapted from ASME B18.2.8. The minimum hole diameters are given. This table also matches the table of recommended clearance holes from ASME B18.2.3.1M.
| Bolt Size | Normal Fit [mm] | Close Fit [mm] | Loose Fit [mm] |
|---|---|---|---|
| M1.6 | 1.8 | 1.7 | 2 |
| M2 | 2.4 | 2.2 | 2.6 |
| M2.5 | 2.9 | 2.7 | 3.1 |
| M3 | 3.4 | 3.2 | 3.6 |
| M4 | 4.5 | 4.3 | 4.8 |
| M5 | 5.5 | 5.3 | 5.8 |
| M6 | 6.6 | 6.4 | 7 |
| M8 | 9 | 8.4 | 10 |
| M10 | 11 | 10.5 | 12 |
| M12 | 13.5 | 13 | 14.5 |
| M14 | 15.5 | 15 | 16.5 |
| M16 | 17.5 | 17 | 18.5 |
| M20 | 22 | 21 | 24 |
| M24 | 26 | 25 | 28 |
| M30 | 33 | 31 | 35 |
| M36 | 39 | 37 | 42 |
| M42 | 45 | 43 | 48 |
| M48 | 52 | 50 | 56 |
| M56 | 62 | 58 | 66 |
| M64 | 70 | 66 | 74 |
| M72 | 78 | 74 | 82 |
| M80 | 86 | 82 | 91 |
| M90 | 96 | 93 | 101 |
| M100 | 107 | 104 | 112 |
Bolt Thread Length
Per ASME B18.2.3.1M, Table 7, "Thread Lengths," the nominal thread length of metric bolts can be found by:
where L is the total bolt length and dnom is the nominal bolt diameter.
Hex Bolt Head Dimensions
The following table of hex bolt head dimensions was adapted from ASME B18.6.7M, Table 14, "Dimensions of Hex Head Machine Screws." This table is used for smaller size hardware.
| Nominal Diameter and Thread Pitch | Width Across Flats | Head Height | ||
|---|---|---|---|---|
| Minimum [mm] | Maximum [mm] | Minimum [mm] | Maximum [mm] | |
| M2 x 0.4 | 3.02 | 3.20 | 1.3 | 1.6 |
| M2.5 x 0.45 | 3.82 | 4.00 | 1.8 | 2.1 |
| M3 x 0.5 | 4.82 | 5.00 | 2.0 | 2.3 |
| M3.5 x 0.6 | 5.32 | 5.50 | 2.3 | 2.6 |
| M4 x 0.7 | 6.78 | 7.00 | 2.6 | 3.0 |
| M5 x 0.8 | 7.78 | 8.00 | 3.3 | 3.8 |
| M6 x 1 | 9.78 | 10.00 | 4.1 | 4.7 |
| M8 x 1.25 | 12.73 | 13.00 | 5.2 | 6.0 |
| M10 x 1.5 | 15.73 | 16.00 | 6.5 | 7.5 |
| M12 x 1.75 | 17.73 | 18.00 | 7.8 | 9.0 |
The following table of hex bolt head dimensions was adapted from ASME B18.2.3.1M, Table 3, "Dimensions of Hex Cap Screws."
| Nominal Diameter and Thread Pitch | Width Across Flats | Head Height | ||
|---|---|---|---|---|
| Minimum [mm] | Maximum [mm] | Minimum [mm] | Maximum [mm] | |
| M5 x 0.8 | 7.78 | 8.00 | 3.35 | 3.65 |
| M6 x 1 | 9.78 | 10 | 3.85 | 4.15 |
| M8 x 1.25 | 12.73 | 13.00 | 5.10 | 5.50 |
| M10 x 1.5 | 15.73 | 16.00 | 6.17 | 6.63 |
| M12 x 1.75 | 17.73 | 18.00 | 7.24 | 7.76 |
| M14 x 2 | 20.67 | 21.00 | 8.51 | 9.09 |
| M16 x 2 | 23.67 | 24.00 | 9.68 | 10.32 |
| M20 x 2.5 | 29.16 | 30.00 | 12.12 | 12.88 |
| M24 x 3 | 35.00 | 36.00 | 14.46 | 15.44 |
| M30 x 3.5 | 45.00 | 46.00 | 17.92 | 19.48 |
| M36 x 4 | 53.80 | 55.00 | 21.62 | 23.38 |
| M42 x 4.5 | 62.90 | 65.00 | 25.03 | 26.97 |
| M48 x 5 | 72.60 | 75.00 | 28.93 | 31.07 |
| M56 x 5.5 | 82.20 | 85.00 | 33.80 | 36.20 |
| M64 x 6 | 91.80 | 95.00 | 38.68 | 41.32 |
| M72 x 6 | 101.40 | 105.00 | 43.55 | 46.45 |
| M80 x 6 | 111.00 | 115.00 | 48.42 | 51.58 |
| M90 x 6 | 125.50 | 130.00 | 54.26 | 57.75 |
| M100 x 6 | 140.00 | 145.00 | 60.10 | 63.90 |
Hex Nut Dimensions
The following table of hex nut dimensions was adapted from ASME B18.2.4.1M, Table 1, "Dimensions of Hex Nuts, Style 1." For further reference, also see ASME B18.2.4.2M, Table 1, "Dimensions of Hex Nuts, Style 2.".
| Nominal Diameter and Thread Pitch | Width Across Flats | Thickness | ||
|---|---|---|---|---|
| Minimum [mm] | Maximum [mm] | Minimum [mm] | Maximum [mm] | |
| M1.6 x 0.35 | 3.02 | 3.20 | 1.05 | 1.30 |
| M2 x 0.4 | 3.82 | 4.00 | 1.35 | 1.60 |
| M2.5 x 0.45 | 4.82 | 5.00 | 1.75 | 2.00 |
| M3 x 0.5 | 5.32 | 5.50 | 2.15 | 2.40 |
| M3.5 x 0.6 | 5.82 | 6.00 | 2.55 | 2.80 |
| M4 x 0.7 | 6.78 | 7.00 | 2.90 | 3.20 |
| M5 x 0.8 | 7.78 | 8.00 | 4.40 | 4.70 |
| M6 x 1 | 9.78 | 10.00 | 4.90 | 5.20 |
| M8 x 1.25 | 12.73 | 13.00 | 6.44 | 6.80 |
| M10 x 1.5 | 15.73 | 16.00 | 8.04 | 8.40 |
| M12 x 1.75 | 17.73 | 18.00 | 10.37 | 10.80 |
| M14 x 2 | 20.67 | 21.00 | 12.10 | 12.80 |
| M16 x 2 | 23.67 | 24.00 | 14.10 | 14.80 |
| M20 x 2.5 | 29.16 | 30.00 | 16.90 | 18.00 |
| M24 x 3 | 35.00 | 36.00 | 20.20 | 21.50 |
| M30 x 3.5 | 45.00 | 46.00 | 24.30 | 25.60 |
| M36 x 4 | 53.80 | 55.00 | 29.40 | 31.00 |
Internal Thread Dimensions
The following equations can be used to calculate internal thread dimensions for ISO metric threads:
| Equation, Metric Units [mm] | Source | |
|---|---|---|
| Minor Diameter | dm.int = dnom − 1.25·H = dnom − 1.08253175·P | Machinery's Handbook |
| Pitch Diameter | dp.int = dnom − 0.75·H = dnom − 0.64951905·P | Machinery's Handbook |
In the table above, dnom is nominal diameter in millimeters and P is the thread pitch in millimeters.
Flat Washer Dimensions
The following table of flat washer dimensions was adapted from ASME B18.22M, Table 1, "Dimensions of Metric Plain Washers (General Purpose)." Plain washers come in 3 series: Regular, Narrow, and Wide.
| Nominal Size | Series | Inner Diameter | Outer Diameter | Thickness | |||
|---|---|---|---|---|---|---|---|
| Min [mm] | Max [mm] | Min [mm] | Max [mm] | Min [mm] | Max [mm] | ||
| M1.6 | Narrow | 1.95 | 2.09 | 3.70 | 4.00 | 0.50 | 0.70 |
| M1.6 | Regular | 1.95 | 2.09 | 4.70 | 5.00 | 0.50 | 0.70 |
| M1.6 | Wide | 1.95 | 2.09 | 5.70 | 6.00 | 0.60 | 0.90 |
| M2 | Narrow | 2.50 | 2.64 | 4.70 | 5.00 | 0.60 | 0.90 |
| M2 | Regular | 2.50 | 2.64 | 5.70 | 6.00 | 0.60 | 0.90 |
| M2 | Wide | 2.50 | 2.64 | 7.64 | 8.00 | 0.60 | 0.90 |
| M2.5 | Narrow | 3.00 | 3.14 | 5.70 | 6.00 | 0.60 | 0.90 |
| M2.5 | Regular | 3.00 | 3.14 | 7.64 | 8.00 | 0.60 | 0.90 |
| M2.5 | Wide | 3.00 | 3.14 | 9.64 | 10.00 | 0.80 | 1.20 |
| M3 | Narrow | 3.50 | 3.68 | 6.64 | 7.00 | 0.60 | 0.90 |
| M3 | Regular | 3.50 | 3.68 | 9.64 | 10.00 | 0.80 | 1.20 |
| M3 | Wide | 3.50 | 3.68 | 11.57 | 12.00 | 1.00 | 1.40 |
| M3.5 | Narrow | 4.00 | 4.18 | 8.64 | 9.00 | 0.80 | 1.20 |
| M3.5 | Regular | 4.00 | 4.18 | 9.64 | 10.00 | 1.00 | 1.40 |
| M3.5 | Wide | 4.00 | 4.18 | 14.57 | 15.00 | 1.20 | 1.75 |
| M4 | Narrow | 4.70 | 4.88 | 9.64 | 10.00 | 0.80 | 1.20 |
| M4 | Regular | 4.70 | 4.88 | 11.57 | 12.00 | 1.00 | 1.40 |
| M4 | Wide | 4.70 | 4.88 | 15.57 | 16.00 | 1.60 | 2.30 |
| M5 | Narrow | 5.60 | 5.78 | 10.57 | 11.00 | 1.00 | 1.40 |
| M5 | Regular | 5.60 | 5.78 | 14.57 | 15.00 | 1.20 | 1.75 |
| M5 | Wide | 5.60 | 5.78 | 19.48 | 20.00 | 1.60 | 2.30 |
| M6 | Narrow | 6.65 | 6.87 | 12.57 | 13.00 | 1.20 | 1.75 |
| M6 | Regular | 6.65 | 6.87 | 18.28 | 18.80 | 1.20 | 1.75 |
| M6 | Wide | 6.65 | 6.87 | 24.88 | 25.40 | 1.60 | 2.30 |
| M8 | Narrow | 8.90 | 9.12 | 18.28 | 18.80 | 1.60 | 2.30 |
| M8 | Regular | 8.90 | 9.12 | 24.88 | 25.40 | 1.60 | 2.30 |
| M8 | Wide | 8.90 | 9.12 | 31.38 | 32.00 | 2.00 | 2.80 |
| M10 | Narrow | 10.85 | 11.12 | 19.48 | 20.00 | 1.60 | 2.30 |
| M10 | Regular | 10.85 | 11.12 | 27.48 | 28.00 | 2.00 | 2.80 |
| M10 | Wide | 10.85 | 11.12 | 38.38 | 39.00 | 2.50 | 3.50 |
| M12 | Narrow | 13.30 | 13.57 | 24.88 | 25.40 | 2.00 | 2.80 |
| M12 | Regular | 13.30 | 13.57 | 33.38 | 34.00 | 2.50 | 3.50 |
| M12 | Wide | 13.30 | 13.57 | 43.38 | 44.00 | 2.50 | 3.50 |
| M14 | Narrow | 15.25 | 15.52 | 27.48 | 28.00 | 2.00 | 2.80 |
| M14 | Regular | 15.25 | 15.52 | 38.38 | 39.00 | 2.50 | 3.50 |
| M14 | Wide | 15.25 | 15.52 | 49.38 | 50.00 | 3.00 | 4.00 |
| M16 | Narrow | 17.25 | 17.52 | 31.38 | 32.00 | 2.50 | 3.50 |
| M16 | Regular | 17.25 | 17.52 | 43.38 | 44.00 | 3.00 | 4.00 |
| M16 | Wide | 17.25 | 17.68 | 54.80 | 56.00 | 3.50 | 4.60 |
| M20 | Narrow | 21.80 | 22.13 | 38.38 | 39.00 | 3.00 | 4.00 |
| M20 | Regular | 21.80 | 22.32 | 49.00 | 50.00 | 3.50 | 4.60 |
| M20 | Wide | 21.80 | 22.32 | 64.80 | 66.00 | 4.00 | 5.10 |
| M24 | Narrow | 25.60 | 26.12 | 43.00 | 44.00 | 3.50 | 4.60 |
| M24 | Regular | 25.60 | 26.12 | 54.80 | 56.00 | 4.00 | 5.10 |
| M24 | Wide | 25.60 | 26.12 | 70.80 | 72.00 | 4.50 | 5.60 |
| M30 | Narrow | 32.40 | 33.02 | 54.80 | 56.00 | 4.00 | 5.10 |
| M30 | Regular | 32.40 | 33.02 | 70.80 | 72.00 | 4.50 | 5.60 |
| M30 | Wide | 32.40 | 33.02 | 88.60 | 90.00 | 5.00 | 6.40 |
| M36 | Narrow | 38.30 | 38.92 | 64.80 | 66.00 | 4.50 | 5.60 |
| M36 | Regular | 38.30 | 38.92 | 88.60 | 90.00 | 5.00 | 6.40 |
| M36 | Wide | 38.30 | 38.92 | 108.60 | 110.00 | 7.00 | 8.50 |
Need a Bolted Joint Calculator?
Check out our bolted joint calculator based on the methodology described here.
- stress analysis of a bolted joint
- accounts for preload, applied axial load, and applied shear load
References
General References:
- Barrett, Richard T., "Fastener Design Manual," NASA Reference Publication 1228, 1990.
- Budynas-Nisbett, "Shigley's Mechanical Engineering Design," 8th Ed.
- Chambers, Jeffrey A., "Preloaded Joint Analysis Methodology for Space Flight Systems," NASA Technical Memorandum 106943, 1995.
- Machinery's Handbook, 27th Ed., Industrial Press Inc., 2004.
- Lindeburg, Michael R., "Mechanical Engineering Reference Manual for the PE Exam," 13th Ed.
Specifications and Standards:
- ASME B1.1, "Unified Inch Screw Threads (UN and UNR Thread Form)," The American Society of Mechanical Engineers, 2003.
- ASME B18.2.1, "Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series)," The American Society of Mechanical Engineers, 2012.
- ASME B18.2.2, "Nuts for General Applications: Machine Screw Nuts, Hex, Square, Hex Flange, and Coupling Nuts (Inch Series)," The American Society of Mechanical Engineers, 2010.
- ASME B18.2.8, "Clearance Holes for Bolts, Screws, and Studs," The American Society of Mechanical Engineers, 1999.
- ASME B18.21.1, "Washers: Helical Spring-Lock, Tooth Lock, and Plain Washers (Inch Series)," The American Society of Mechanical Engineers, 2009.
- FED-STD-H28/2B, "Screw-Thread Standards for Federal Services," Federal Standard, 1991.
