Use this bolt shear stress calculator to calculate the shear stress in a bolt subject to single shear or double shear loading. The calculator uses the applied shear force, bolt diameter, allowable shear stress and safety factor to estimate utilisation and pass/fail result.
This calculator estimates the average shear stress in a circular bolt shank. It can be used for simple bolted joint checks where a bolt is loaded in single shear or double shear.
The calculator provides:
For a more complete bolted joint design, bearing stress, plate shear, preload, fatigue, thread position and bolt grade should also be considered.
Bolt cross-sectional area:
Single shear stress:
Equivalent single shear formula:
Double shear stress:
Equivalent double shear formula:
Design allowable shear stress:
Utilisation:
| Symbol | Description | Units |
|---|---|---|
| F | Applied shear force | N |
| d | Bolt diameter at shear plane | mm |
| A | Bolt cross-sectional area | mm² |
| τsingle | Shear stress in single shear | N/mm² |
| τdouble | Shear stress in double shear | N/mm² |
| τallow | Allowable bolt shear stress | N/mm² |
| SF | Safety factor | - |
Enter the bolt loading and dimensions, then click calculate.
| Result | Meaning |
|---|---|
| Bolt area | The circular cross-sectional area of the bolt at the shear plane. |
| Single shear stress | The average shear stress when the bolt is cut by one shear plane. |
| Double shear stress | The average shear stress when the bolt is cut by two shear planes. For the same load and diameter, this is half the single shear stress. |
| Design allowable stress | The allowable bolt shear stress divided by the selected safety factor. |
| Utilisation | The calculated shear stress divided by the design allowable stress. A value below 100% passes this simplified check. |
This calculator checks average shear stress in a circular bolt section. It does not check all possible bolted joint failure modes.
| This Calculator Includes | This Calculator Does Not Include |
|---|---|
| Single shear stress | Bolt tensile stress |
| Double shear stress | Bearing stress in the plate |
| Bolt cross-sectional area | Plate edge shear or tear-out |
| Utilisation against selected allowable shear stress | Thread stripping or nut failure |
| Safety factor adjustment | Fatigue, preload, friction-grip behaviour or joint slip |
For bolt bearing stress, use the Bolt Bearing Stress Calculator.
For eccentric bolt groups, use the Bolt Group Eccentric Load Calculator.
Bolt shear stress is calculated by dividing the applied shear force by the shear area. In single shear, there is one shear plane. In double shear, the load is resisted by two shear planes.
If the bolt thread is located in the shear plane, the effective shear area may be less than the nominal shank area. For conservative checks, the tensile stress area or thread root area may need to be considered instead of the nominal bolt diameter.
This calculator assumes the applied shear load is shared by one bolt. For multiple bolts, divide the total load between the bolts according to the joint arrangement before using this calculator.
For further bolted joint theory, see the RoyMech reference page: Bolted Joint Design and Calculations.
For the full calculator section, see: Bolted Joint Calculators.
Bolt shear stress is calculated by dividing the applied shear force by the bolt shear area. For a circular bolt in single shear:
where F is the applied shear force and d is the bolt diameter.
In single shear there is one shear plane through the bolt. In double shear there are two shear planes, so the same applied load is shared over twice the shear area.
For the same bolt diameter and applied force, double shear gives approximately half the shear stress of single shear because the force is resisted by two shear planes.
Use the diameter at the shear plane. If the plain shank is in the shear plane, the nominal shank diameter is normally used. If the thread is in the shear plane, the effective diameter may be smaller and a reduced area should be considered.
No. This calculator checks bolt shear stress only. Bearing stress between the bolt and plate should be checked separately.
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, material properties, loading conditions, fatigue requirements and safety factors.