JUJUMI工程计算器 · Engineering Calculators

Three-Wire Thread

Compute thread pitch diameter d₂ from a three-wire measurement M, wire diameter, pitch and thread angle (incl. 60° metric form).

Inputs

Formula

d₂ = M − dw(1 + 1/sin(α/2)) + P/(2 tan(α/2))
M = d − 3d_w + 0.866 p
Three-Wire Thread schematic

How to use

  1. Fill in Reading M, Pitch P, Thread angle α, Wire dia. dw in the Inputs section (watch the unit on each field).
  2. Click Calculate; the tool evaluates the formula shown above.
  3. Read Pitch dia. d₂ in the results area.
Formula notesThree-wire method: M = d₂ − 3·d_w + 0.866·p (d_w wire dia, p pitch, d₂ pitch dia).