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# Bolt Circle pattern Calculator

Bolt circle hole pattern calculator
 Bolt circle diameter: Hole diameter: Number of holes: Start angle: Output Unit Precision 1 2 3 4 5
 Hole position data
 NC format listing

### Glossary

Units of measure:
The units of measure used when defining a bolt circle hole list must all be of the same type, for example: all in inches or all in millimetres.
Hole diameter:
The diameter of the holes that are equally distributed around the bolt circle diameter
Bolt circle diameter:
the diameter of the circle on which the holes will be evenly distributed.
Start angle:
The 0° angle is to the right in the "X" axis and aligned with the center of the bolt circle in the "Y" axis. The angle is described as...
- A positive angle is counterclockwise
- A negative angle is clockwise. ex:-45° = 315°
Angle units
360° = 21,600 minutes = 1,296,000 seconds = 6.2832 radians = full circle
(1 degree) = 60 minutes = 3,600 seconds = 0.0175 radian
0°1' (1 minute of a degree) = .016 degree = 60 seconds = .000298 radian
0°0'1" (1 second of a degree) = .00027 degree = .0000048 radian
Angle entry field (Convert decimal angle to; degrees, minutes and seconds)
Angle format example 1: decimal 15.5° enter as 15.5 no formating needed.
Angle format example 2: 64°45'34" enter as 64d45m34s
Angle format example 3: -30°5' enter as -30d5m
Angle format example 4: 15°0'10" enter as 15d10s
Angle format example 5: -0°0'50" enter as -50s

Last Updated: 27 February 2012

 Decimal Degree Sexagesimal Degree
 Fraction Convert
 Fraction inch mm
 1/256 0.0039 0.1 1/128 0.0078 0.2 1/64 0.0156 0.4 1/32 0.0313 0.79 3/64 0.0469 1.19 1/16 0.0625 1.59 3/32 0.0938 2.38 7/64 0.1094 2.78 1/8 0.125 3.18 9/64 0.1406 3.57 5/32 0.1563 3.97 11/64 0.1719 4.37 3/16 0.1875 4.76 13/64 0.2031 5.16 7/32 0.2188 5.56 15/64 0.2344 5.95 1/4 0.25 6.35 5/16 0.3125 7.94 21/64 0.3281 8.33 11/32 0.3438 8.73 23/64 0.3594 9.13 25/64 0.3906 9.92 13/32 0.4063 10.32 27/64 0.4219 10.72 7/16 0.4375 11.11 29/64 0.4531 11.51 15/32 0.4688 11.91 31/64 0.4844 12.3 1/2 0.5 12.7 33/64 0.5156 13.1 17/32 0.5313 13.49 35/64 0.5469 13.89 9/16 0.5625 14.29 37/64 0.5781 14.68 19/32 0.5938 15.08 39/64 0.6094 15.48 5/8 0.625 15.88 41/64 0.6406 16.27 21/32 0.6563 16.67 43/64 0.6719 17.07 11/16 0.6875 17.46 45/64 0.7031 17.86 23/32 0.7188 18.26 47/64 0.7344 18.65 3/4 0.75 19.05 49/64 0.7656 19.45 25/32 0.7813 19.84 51/64 0.7969 20.24 13/16 0.8125 20.64 53/64 0.8281 21.03 27/32 0.8438 21.43 55/64 0.8594 21.83 7/8 0.875 22.23 57/64 0.8906 22.62 29/32 0.9063 23.02 59/64 0.9219 23.42 15/16 0.9375 23.81 61/64 0.9531 24.21 61/64 0.9531 24.21 31/32 0.9688 24.61 63/64 0.9844 25 1 1 25.4

18 August 2011