METRICcoarse60° flank
M56 × 5.5 Thread Dimensions
M56 x 5.5 is a coarse pitch METRIC thread. Pitch is 5.5 mm, equivalent to 4.62 threads per inch. The recommended tap drill leaves roughly 75% thread engagement.
Nominal Ø56 mm
Pitch5.5 mm
Threads per inch4.62
Pitch Ø52.43 mm
Tap drill50.5 mm
Thread profile
millimetres unless stated- Designation
- M56 x 5.5
- Thread system
- METRIC
- Series
- coarse
- Flank angle
- 60°
- Major diameter
- 56 mm / 2.2"
- Pitch
- 5.5 mm
- Threads per inch
- 4.62
- Pitch diameter
- 52.43 mm
- Minor diameter (external)
- 49.25 mm
- Minor diameter (internal)
- 50.05 mm
- Thread depth
- 3.37 mm
- Recommended tap drill
- Ø 50.5 mm / 1.99"
How these values are derived
Basic ISO thread geometry uses the fundamental triangle height H = 0.866025 × P. External minor diameter d₃ = d − 1.226869 × P, internal minor diameter D₁ = d − 1.082532 × P. Tap drill is given as nominal diameter minus pitch, which approximates a 75% thread engagement — adjust for tough materials or deep holes.