Bolt Circle Diameter Calculator

Bolt Circle Diameter Formula:

\[ B = G_o + (2 \times d_b) + 12 \]

Bolt Circle Diameter: mm

1. What is Bolt Circle Diameter?

Definition: Bolt Circle Diameter (BCD) is the diameter of the circle on which the bolt holes will be evenly distributed.

Purpose: It's crucial for proper alignment and distribution of forces in flanged connections, wheels, and other circular bolt patterns.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ B = G_o + (2 \times d_b) + 12 \]

Where:

\( B \) — Bolt Circle Diameter (mm)
\( G_o \) — Outside Diameter of Gasket (mm)
\( d_b \) — Nominal Bolt Diameter (mm)
12 — Standard additional allowance (mm)

Explanation: The formula calculates the diameter needed to accommodate the gasket, bolts, and standard clearance.

3. Importance of Bolt Circle Diameter

Details: Proper BCD calculation ensures proper bolt spacing, even load distribution, and prevents leakage in flanged connections.

4. Using the Calculator

Tips: Enter the gasket outside diameter, nominal bolt diameter, and tolerance percentage (default ±5%). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a +12 in the formula?
A: This accounts for standard clearance between bolt holes and gasket edge to ensure proper sealing and structural integrity.

Q2: What's a typical tolerance for BCD?
A: ±5% is common, but this may vary based on application requirements and engineering standards.

Q3: Can I use this for non-gasket applications?
A: Yes, for any circular bolt pattern, though the +12 allowance might need adjustment based on specific requirements.

Q4: How does bolt diameter affect BCD?
A: Larger bolts require more space, thus increasing the BCD proportionally (2× bolt diameter is added).

Q5: What if I have a specific standard to follow?
A: Adjust the formula constants (+12) and tolerance as required by your specific standard or engineering guidelines.