Diameter of bolt pitch circle given torque resisted by one bolt Calculator

Diameter of bolt pitch circle Formula:

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

Torque resisted by bolt:

N·m

Shear Stress in Bolt:

Diameter of Bolt:

Tolerance:

Diameter of bolt pitch circle (m):

1. What is Diameter of bolt pitch circle?

Definition: The diameter of the circle that passes through the center of all bolts in a circular bolt pattern.

Purpose: It's a critical measurement in mechanical engineering for designing bolted joints that resist torque.

2. How Does the Calculator Work?

The calculator uses the formula:

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

Where:

\( d_{pitch} \) — Diameter of bolt pitch circle (meters)
\( T_{bolt} \) — Torque resisted by one bolt (Newton-meters)
\( f_s \) — Shear stress in bolt (Pascals)
\( d_{bolt} \) — Diameter of individual bolt (meters)

Explanation: The formula calculates the required pitch circle diameter based on the torque capacity of a single bolt and its material properties.

3. Importance of Pitch Circle Diameter

Details: Proper calculation ensures bolted joints can withstand applied torques without failure, while optimizing material usage and joint size.

4. Using the Calculator

Tips: Enter the torque resisted by one bolt, shear stress in the bolt material, bolt diameter, and optional tolerance percentage. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the tolerance percentage for?
A: It allows for design margin (±5%) to account for manufacturing variations or safety factors.

Q2: How do I determine the shear stress in the bolt?
A: This is typically a material property from specifications (e.g., 140 MPa for Grade 8.8 bolts).

Q3: Can I use this for non-circular bolt patterns?
A: No, this calculator is specifically for circular bolt patterns. Other patterns require different calculations.

Q4: What if I have multiple bolts resisting torque?
A: Divide the total torque by the number of bolts to get the torque per bolt for this calculation.

Q5: Does this account for preload in the bolts?
A: No, this is a simplified calculation. For precise designs, consider bolt preload and joint stiffness.