6 reference tools
Bolt Calculators: Torque, Preload & Joint Stiffness
Estimate bolt torque and preload, bolt and clamped-member stiffness, external load sharing, joint separation, and thermal preload change.
Where should you start with a preloaded bolted joint?
Use torque–preload estimation for installation inputs, stiffness tools for the bolt and clamped load paths, and load sharing for an external tensile load. Use the thermal tool when bolt and member expansion differ. Distinguish initial preload from retained preload, and a linear separation projection from a conservative preload-only check. Nut factors, preload variation, and effective lengths require evidence for the actual joint.
Choose a calculator
- #032
Bolted Joint External Load Sharing and Separation Calculator
Calculate preloaded-joint bolt load increase, clamp relief, linear separation load, and a separate conservative preload-only reserve.
- #033
Bolt Axial Stiffness Calculator
Calculate bolt axial stiffness from shank and threaded effective lengths, tensile stress area, and elastic modulus using a series-compliance model.
- #034
Bolted Joint Clamped-Member Stiffness Calculator
Estimate symmetric clamped-member stiffness using compression frusta, a diameter limit, homogeneous material modulus, and joint geometry.
- #035
Multi-Layer Bolted Joint Clamped-Member Stiffness Calculator
Estimate three-layer clamped-member stiffness with separate material moduli, unequal bearing faces, segmented compression zones, and a diameter limit.
- #036
Bolted Joint Thermal Preload Change Calculator
Calculate signed thermal preload change from bolt and member expansion, compatible axial stiffnesses, effective lengths, and temperature changes.
- #037
Bolt Torque / Preload Calculator
Estimate bolt preload from tightening torque, or torque from target preload, with nut factor, running torque, installation tolerance, and variation.
Before you use the result
- Establish a representative nut factor, running torque, installation tolerance, and preload variation before using the empirical torque relationship.
- Calculate compatible bolt and member stiffnesses with defensible effective lengths and compression-zone assumptions.
- Review the retained preload after relevant losses and thermal changes before evaluating external load sharing. Strength, fatigue, thread stripping, and installation acceptance remain separate checks.
Each linked tool includes its own formulas, worked examples, input units, limitations, and source notes. See how MechClarity documents and checks its calculations.
Continue with related calculations
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