Other toolsPiston forceCylinder speedGear ratioCNC cuttingCycle timeDrill / tapHardnessPress brakeBend unfoldLaser cuttingStock massCAD viewer
Bolt torque calculator
Metric coarse tightening torque and clamp load from diameter, pitch, ISO 898-1 class and dry / oiled / coated nut factor.
K-factor estimate at a chosen fraction of proof load. Friction, coating, prevailing torque and joint stiffness dominate — follow the drawing or VDI 2230.
Inputs
Metric coarse
Thread Ø
mm
Pitch
mm
Preload · 70%
Fraction of proof load (typical 70%).
Results
Tightening torque
41.6N·m
≈ 4.24 kg·m
- Clamp load
- 26 kN
- ≈ 2,649 kgf
- Proof load
- 37.1 kN
- Rp 640 MPa
- Stress area As
- 58 mm²
- Nut factor K
- 0.16
- Oiled · K=0.16
Formulas
As = π/4 · (d − 0.9382 P)² F = η · As · Rp
T = K · F · d dry 0.20 · oiled 0.16 · coated 0.12
Need motion hardware that matches these numbers?
Explore the TDR lineup or talk to applications engineering.