Bolt Circle Diameter Calculator

Enter values below to calculate the diameter of a bolt circle.

Tip:

To measure the center distance between two holes of equal diameter with an electronic caliper.

1. Use the inside jaws to measure the diameter of one of the holes. Before you remove the caliper from the hole, press the button to zero the caliper while it is set to the diameter of the hole.

2. Still using the inside jaws, measure the distance between the far surfaces of the two holes. The caliper reading is the distance between centers of the two holes.

Tap & Die Set, 39-Piece Solid Round Dies

39-piece machine screw & fractional tap and solid round die set
Machine screw and fractional sizes of plug style taps plus 1" solid round dies
Includes three tap handles and two die stocks
18-leaf standard thread pitch gauge and screwdriver
Plastic case with lift-out tray

$269.95

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Tooling Package, Mini Lathe, 0XA QCTP

QCTP Set easily mounts to 7x10, 7x12, 7x14, 7x16 lathes
3/8" indexable TCMT inserts, P1N cut-off blade
9-piece carbide boring bar set - 3/8" shank
1/2" drill chuck, 2MT short to 33JT drill chuck arbor
4 center drills (sizes 1-4)

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Bell Punch Center Finder

A handy tool if with you require precise drilling on round stock.
Works on stock up to 35mm (1 3/8")
Made of hardened steel - 48-52 HRC
Overall length 80 mm (3-9/64")
Shank length and diameter 9.5mm (3/8")

$19.95

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