METRICfine60° flank

M30 × 2 fine Thread Dimensions

M30 x 2 (fine) is a fine pitch METRIC thread. Pitch is 2 mm, equivalent to 12.7 threads per inch. The recommended tap drill leaves roughly 75% thread engagement.

Nominal Ø30 mm
Pitch2 mm
Threads per inch12.7
Pitch Ø28.7 mm
Tap drill28 mm

Thread profile

millimetres unless stated
Thread profile — M30 x 2 (fine)d 30d2 28.7d3 27.55mm60°P 2h3 1.23tap ⌀28
M30 × 2 fine — basic profile60° flank angle · Not to scale
Designation
M30 x 2 (fine)
Thread system
METRIC
Series
fine
Flank angle
60°
Major diameter
30 mm / 1.18"
Pitch
2 mm
Threads per inch
12.7
Pitch diameter
28.7 mm
Minor diameter (external)
27.55 mm
Minor diameter (internal)
27.83 mm
Thread depth
1.23 mm
Recommended tap drill
Ø 28 mm / 1.1"

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.