METRICfine60° flank

M20 × 1.5 fine Thread Dimensions

M20 x 1.5 (fine) is a fine pitch METRIC thread. Pitch is 1.5 mm, equivalent to 16.93 threads per inch. The recommended tap drill leaves roughly 75% thread engagement.

Nominal Ø20 mm
Pitch1.5 mm
Threads per inch16.93
Pitch Ø19.03 mm
Tap drill18.5 mm

Thread profile

millimetres unless stated
Thread profile — M20 x 1.5 (fine)d 20d2 19.03d3 18.16mm60°P 1.5h3 0.92tap ⌀18.5
M20 × 1.5 fine — basic profile60° flank angle · Not to scale
Designation
M20 x 1.5 (fine)
Thread system
METRIC
Series
fine
Flank angle
60°
Major diameter
20 mm / 0.79"
Pitch
1.5 mm
Threads per inch
16.93
Pitch diameter
19.03 mm
Minor diameter (external)
18.16 mm
Minor diameter (internal)
18.38 mm
Thread depth
0.92 mm
Recommended tap drill
Ø 18.5 mm / 0.73"

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.

Fasteners using this thread66 specification pages

All M20 fasteners
DIN 912ISO 4762DIN 7991ISO 10642DIN 933ISO 4017DIN 931ISO 4014
SpecificationLength (mm)
DIN 912 M20 × 30 Hexagon Socket Head Cap Screw30
DIN 912 M20 × 35 Hexagon Socket Head Cap Screw35
DIN 912 M20 × 40 Hexagon Socket Head Cap Screw40
DIN 912 M20 × 50 Hexagon Socket Head Cap Screw50
DIN 912 M20 × 60 Hexagon Socket Head Cap Screw60
DIN 912 M20 × 80 Hexagon Socket Head Cap Screw80
DIN 912 M20 × 100 Hexagon Socket Head Cap Screw100
ISO 4762 M20 × 30 Hexagon Socket Head Cap Screw30
ISO 4762 M20 × 35 Hexagon Socket Head Cap Screw35
ISO 4762 M20 × 40 Hexagon Socket Head Cap Screw40
ISO 4762 M20 × 50 Hexagon Socket Head Cap Screw50
ISO 4762 M20 × 60 Hexagon Socket Head Cap Screw60
ISO 4762 M20 × 80 Hexagon Socket Head Cap Screw80
ISO 4762 M20 × 100 Hexagon Socket Head Cap Screw100
DIN 7991 M20 × 30 Hexagon Socket Countersunk Head Screw30
DIN 7991 M20 × 35 Hexagon Socket Countersunk Head Screw35
DIN 7991 M20 × 40 Hexagon Socket Countersunk Head Screw40
DIN 7991 M20 × 50 Hexagon Socket Countersunk Head Screw50
DIN 7991 M20 × 60 Hexagon Socket Countersunk Head Screw60
DIN 7991 M20 × 80 Hexagon Socket Countersunk Head Screw80
DIN 7991 M20 × 100 Hexagon Socket Countersunk Head Screw100
ISO 10642 M20 × 30 Hexagon Socket Countersunk Head Screw30
ISO 10642 M20 × 35 Hexagon Socket Countersunk Head Screw35
ISO 10642 M20 × 40 Hexagon Socket Countersunk Head Screw40
ISO 10642 M20 × 50 Hexagon Socket Countersunk Head Screw50
ISO 10642 M20 × 60 Hexagon Socket Countersunk Head Screw60
ISO 10642 M20 × 80 Hexagon Socket Countersunk Head Screw80
ISO 10642 M20 × 100 Hexagon Socket Countersunk Head Screw100
DIN 933 M20 × 30 Hexagon Head Screw / Bolt — Full Thread30
DIN 933 M20 × 35 Hexagon Head Screw / Bolt — Full Thread35
DIN 933 M20 × 40 Hexagon Head Screw / Bolt — Full Thread40
DIN 933 M20 × 50 Hexagon Head Screw / Bolt — Full Thread50
DIN 933 M20 × 60 Hexagon Head Screw / Bolt — Full Thread60
DIN 933 M20 × 70 Hexagon Head Screw / Bolt — Full Thread70
DIN 933 M20 × 80 Hexagon Head Screw / Bolt — Full Thread80
DIN 933 M20 × 100 Hexagon Head Screw / Bolt — Full Thread100
DIN 933 M20 × 120 Hexagon Head Screw / Bolt — Full Thread120
ISO 4017 M20 × 30 Hexagon Head Screw — Full Thread, Product Grade A/B30
ISO 4017 M20 × 35 Hexagon Head Screw — Full Thread, Product Grade A/B35
ISO 4017 M20 × 40 Hexagon Head Screw — Full Thread, Product Grade A/B40

Showing the first 40 of 66 specification pages.