Construction

Bolt Circle Calculator

Find the angular spacing and chord between bolts.

Calculated Output

Angle between bolts (°) 60

Center-to-center spacing 0.5

Formula: angle = 360 ÷ bolts ; chord = BCD × sin(180 ÷ bolts)

Step-by-Step Breakdown

1. Values used:

2. Number of bolts = 6

3. Bolt circle diameter = 1

5. Angle between bolts = 60°

6. Center-to-center spacing = 0.5

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The math behind it

angle between bolts = 360° ÷ bolt count; center-to-center chord = BCD × sin(180° ÷ bolts).

6 bolts on a 5 in BCD → 60° apart, 2.5 in chord.

Chord length?

It's the straight-line distance between two adjacent bolt centers.