Total torque resisted by n number of bolts Calculator

Torque Formula:

\[ T_{bolt} = \frac{n \times f_s \times \pi \times d_{bolt}^2 \times d_{pitch}}{8} \]

Number of Bolts:

Shear Stress in Bolt:

Diameter of Bolt:

Diameter of bolt pitch circle:

Tolerance:

Torque resisted by bolts (N·m):

Minimum Torque (±5%):

Maximum Torque (±5%):

1. What is Torque Resisted by Bolts?

Definition: This calculator determines the total torque that can be resisted by a specified number of bolts based on their shear stress, diameter, and pitch circle diameter.

Purpose: It helps mechanical engineers and designers calculate the torque capacity of bolted connections in various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ T_{bolt} = \frac{n \times f_s \times \pi \times d_{bolt}^2 \times d_{pitch}}{8} \]

Where:

\( T_{bolt} \) — Total torque resisted by bolts (N·m)
\( n \) — Number of bolts
\( f_s \) — Shear stress in bolt (Pa)
\( d_{bolt} \) — Diameter of bolt (m)
\( d_{pitch} \) — Diameter of bolt pitch circle (m)

Explanation: The formula calculates the combined torque resistance of multiple bolts in a circular pattern.

3. Importance of Torque Calculation

Details: Proper torque calculation ensures bolted connections can withstand applied loads without failure, maintaining structural integrity.

4. Using the Calculator

Tips: Enter the number of bolts, shear stress, bolt diameter, pitch circle diameter, and tolerance percentage (default ±5%). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is bolt pitch circle diameter?
A: It's the diameter of the circle that passes through the center of all bolts in a circular pattern.

Q2: Why include a tolerance percentage?
A: Tolerance accounts for variations in material properties, manufacturing tolerances, and installation differences.

Q3: What's a typical shear stress for bolts?
A: This varies by material, but common steel bolts might have shear stress values between 140-400 MPa.

Q4: How does bolt diameter affect torque resistance?
A: Torque resistance increases with the square of bolt diameter, so small diameter increases have large effects.

Q5: Can this be used for non-circular bolt patterns?
A: No, this formula specifically applies to circular bolt patterns. Other patterns require different calculations.