Cola de milano

Dovetail measurement over pins formula

Dovetail slides and grooves are measured indirectly using precision pins (or wires) and a micrometer. The measurement over pins method provides an accurate check of the dovetail angle and width without needing an optical comparator.

• Measurement over pins = dovetail width + (2 × height) / tan(angle)
• For 60 deg dovetails: measurement ≈ width + 1.155 × height
• Standard dovetail angles: 45 deg (O-ring grooves), 60 deg (machine slides), 55 deg (BS standard)

How to use this Dovetail Measurement Calculator

Enter the dovetail width (at the narrowest point), height, and angle. The calculator gives the measurement over pins. Use this to set your micrometer or caliper when inspecting dovetails. For female dovetails, subtract the pin contribution instead of adding.