Bolt Circle Calculator

Calculate Bolt Circle Dimensions

About Bolt Circle Calculations

Bolt circle calculations are essential for precise hole drilling and bolt placement in mechanical assemblies.

Coordinate Formula:

X = R × cos(θ)
Y = R × sin(θ)

Where:

  • R = Bolt circle radius
  • θ = Angle from reference
  • X, Y = Bolt coordinates

Common Applications:

• Flange connections
• Wheel mounting
• Gear assemblies
• Pump housings
• Motor mounts

Standard Patterns:

  • 3-bolt: 120° spacing
  • 4-bolt: 90° spacing
  • 6-bolt: 60° spacing
  • 8-bolt: 45° spacing

Precision Requirements:

• ±0.001" for critical applications
• ±0.005" for general use
• ±0.010" for rough work
• Use proper drilling techniques

Accurate bolt circle calculations ensure proper alignment and load distribution in mechanical connections.