Metric Thread Dimensions Calculator (M10×1.5, Tensile Stress Area)
Pitch diameter, minor diameters, thread depth and tensile stress area of any ISO metric thread, plus the axial load at a stress you choose.
Results
What this tool does
A bolt does not carry load over its full nominal diameter: the threads cut away material, so strength is worked out on the tensile stress area, taken as a circle with the mean of the pitch and minor diameters (ISO 898-1). For an M10×1.5 that is about 58 mm², not the 78.5 mm² of the shank. The dimensions follow from the 60° fundamental triangle of height H = 0.866 p, and the nut's minor diameter D1 is the basic size used to choose a tapping drill. These are basic (nominal) values; real threads carry tolerances.
Formula
H = 0.866 p · d2 = d − 0.6495 p · d3 = d − 1.2269 p · D1 = d − 1.0825 p · A_s = π/4 × ((d2 + d3) ÷ 2)² (ISO 68-1, ISO 898-1)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
d | Nominal diameter (M…) | mm |
p | Pitch | mm |
st | Stress you want to apply to the bolt | MPa |
AS | Tensile stress area | mm² |
D2 | Pitch diameter d2 | mm |
D3 | Minor diameter of the bolt d3 | mm |
D1 | Minor diameter of the nut D1 | mm |
H3 | Thread depth of the bolt h3 | mm |
F | Axial load at that stress | kN |
Worked example
- Nominal diameter (M…)10 mm
- Pitch1.5 mm
- Stress you want to apply to the bolt400 MPa
- Tensile stress area57.99 mm²
- Pitch diameter d29.026 mm
- Minor diameter of the bolt d38.160 mm
- Minor diameter of the nut D18.376 mm
- Thread depth of the bolt h30.920 mm
- Axial load at that stress23.20 kN
Limitations
- For work that must comply with a standard or be signed off, check the result against the applicable code and have it reviewed by a qualified engineer.
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.