Use this bolt combined stress calculator to estimate the equivalent stress in a bolt subject to both tensile load and shear load. The calculator uses the Von Mises stress method to combine tensile stress and shear stress, then compares the result against a selected allowable or yield stress.
This calculator checks a bolt subject to combined axial tension and transverse shear. It calculates bolt area, tensile stress, shear stress, Von Mises equivalent stress, design allowable stress, utilisation and factor of safety.
The calculator provides:
This calculator is useful for bolts where direct shear and axial tension act together, such as bracket connections, bolted supports, lifting plates and mechanically loaded joints.
Bolt cross-sectional area:
Tensile stress:
Shear stress:
Von Mises equivalent stress:
Design allowable stress:
Factor of safety:
Utilisation:
| Symbol | Description | Units |
|---|---|---|
| Ft | Axial tensile load | N |
| Fs | Transverse shear load | N |
| d | Bolt diameter or effective diameter | mm |
| A | Bolt cross-sectional area | mm² |
| σ | Tensile stress | N/mm² |
| τ | Shear stress | N/mm² |
| σvm | Von Mises equivalent stress | N/mm² |
| σallow | Allowable or yield stress | N/mm² |
| SF | Safety factor | - |
Enter the bolt loading and dimensions, then click calculate.
| Result | Meaning |
|---|---|
| Tensile stress | The axial tensile stress in the bolt caused by the tensile load. |
| Shear stress | The average shear stress in the bolt caused by the transverse shear load. |
| Von Mises equivalent stress | A combined stress value used to compare tensile and shear loading against a single stress limit. |
| Design allowable stress | The selected allowable or yield stress divided by the safety factor. |
| Factor of safety | The ratio of allowable or yield stress to the calculated Von Mises stress. |
| Utilisation | The Von Mises equivalent stress divided by the design allowable stress. A value below 100% passes this simplified check. |
This calculator checks a simplified combined tensile and shear stress condition in a bolt. It does not check every possible bolted joint failure mode.
| This Calculator Includes | This Calculator Does Not Include |
|---|---|
| Tensile stress from axial load | Bolt preload effects |
| Shear stress from transverse load | Joint slip or friction-grip behaviour |
| Von Mises equivalent stress | Bearing stress between bolt and plate |
| Factor of safety and utilisation | Plate shear, tear-out or net section failure |
| Simple circular bolt area | Fatigue, prying action or thread stripping |
For bolt shear stress only, use the Bolt Shear Stress Calculator.
For bolt bearing stress, use the Bolt Bearing Stress Calculator.
For eccentric bolt group forces, use the Bolt Group Eccentric Load Calculator.
For ductile metallic bolts, the Von Mises stress method is commonly used to combine tensile stress and shear stress into a single equivalent stress. This equivalent stress can then be compared with an allowable or yield stress.
This calculator uses the circular bolt area based on the entered diameter. If the threaded portion of the bolt is critical, the tensile stress area or thread root area may be more appropriate than the nominal shank diameter.
A complete bolted joint design may also need to consider preload, joint stiffness, fatigue, bolt grade, thread engagement, nut strength, bearing stress, plate shear, edge distance and design standard requirements.
For further bolted joint theory, see the RoyMech reference page: Bolted Joint Design and Calculations.
For the full calculator section, see: Bolted Joint Calculators.
Combined stress in a bolt can be estimated using the Von Mises equivalent stress formula:
where σ is tensile stress and τ is shear stress.
Von Mises stress is an equivalent stress used to assess ductile materials under combined loading. It allows tensile and shear stresses to be compared against a single allowable or yield stress.
Combined bolt stress should be checked when a bolt is subject to both axial tensile load and transverse shear load.
Use the area at the critical section. If the plain shank is critical, the shank diameter may be used. If the threaded portion is critical, the tensile stress area or thread root area may be more appropriate.
No. This calculator does not include preload effects. Preload can significantly change the stress state in a bolted joint and should be considered separately where relevant.
This calculator is intended for preliminary engineering calculations and educational use. Final bolted joint design should be checked against the relevant design standard, bolt grade, preload method, fatigue requirements and safety factors.