Engineering DisclaimerEngineering calculations are provided for preliminary design and educational/reference purposes only. Users must verify all results according to applicable engineering standards, supplier data, manufacturing requirements, and professional engineering judgment.
VDI 2230
Fasteners
Bolted Joint Torque & Preload
Calculate target tightening torque and clamping preload for metric and imperial fasteners using friction coefficient indices.
Workspace Mode:
Unsaved Configuration
Calculation Results
Clamp Preload Force (Fi)
15kN
Initial clamping tension.
Tightening Torque (Ta)
15N·m
Target installation wrench torque.
Calculation Summary
Input Parameters
| Nominal Thread Diameter | 12mm |
| Torque Coefficient (K) | 0.2 |
| Thread Proof Strength | 600MPa |
| Utilization Factor (η) | 0.75 |
Calculated Results
| Clamp Preload Force (Fi) | 15.00kN KEY |
| Tightening Torque (Ta) | 15.00N·m |
Safety Notes
This is a dynamic placeholder interface. Calculations will activate in a future release.
Mathematical Models & Equations
Clamp Preload Force
Fi = η * A_s * S_pTightening Torque
Ta = K * Fi * dVerification Calculation Log
- 1Retrieve input parameters from form controls.
- 2Substitute first active variable: Input = 12.
- 3Sprint 3 Placeholder: Formula computations will activate in future releases.
Engineering Application Notes
Torque-preload K-factor equations are linear approximations. Actual preloads can vary by ±25% depending on lubrication, tightening speed, and thread quality.
Standard Citations & References
- VDI 2230: Systematic Calculation of High-Duty Bolted Joints
- Shigley's Mechanical Engineering Design, Chapter 8