Metric coarse

M10 × 1.5

Tap drill 8.5 mm for a M10 × 1.5 thread — major Ø 10 mm, pitch 1.5 mm (16.93 TPI).

Tap drill
8.5 mm
8.5 mm · ≈77% thread

Profile

Thread form & key diameters

Major Ø 10 mmP 1.5 mm60°Minor Ø 8.16 mm · Pitch Ø 9.026 mmM10 × 1.516.93 TPI · 60° form

Dimensions

DesignationM10 × 1.5
Major (outside) diameter10 mm · 0.3937"
Pitch1.5 mm · 16.93 TPI
Pitch diameter9.026 mm · 0.3553"
Minor diameter (external)8.16 mm · 0.3212"
Minor diameter (internal)8.376 mm · 0.3298"
Recommended tap drill8.5 mm · ≈77% thread
Clearance holeClose 10.5 · Normal 11 · Loose 12 mm
Hex head (across flats)16 mm
Socket key (across flats)8 mm

ISO 273 clearance holes (fine / medium / coarse).

Tightening torque estimate

Target preload is 75% of proof load; torque is estimated from T = K · F · d.

Grade / classStress areaPreloadTorque
Class 8.858 mm²25.23 kN50.5 N·m
Class 10.958 mm²36.1 kN72.2 N·m
Class 12.958 mm²42.19 kN84.4 N·m
These figures assume a nut factor of K = 0.20 (dry / as-received steel). K captures thread and head friction and can swing torque by 30% or more — a lubricated joint needs noticeably less. Change the lubrication assumption in the bolt-torque calculator.

What tap drill do I need for M10 × 1.5?

For a M10 × 1.5 thread, drill the hole with a 8.5 mm tap drill (8.5 mm — the standard D − P rule) before tapping. That produces roughly 77% thread engagement, the usual target for a strong, tappable hole. The mating bolt has a major diameter of 10 mm and a pitch of 1.5 mm (16.93 TPI).

To pass a M10 × 1.5 bolt through a part rather than thread it, use a clearance hole: Close 10.5 · Normal 11 · Loose 12 mm.

All values are generated from the standard thread formulas (ISO 68-1 / ASME B1.1) and published standard tables — not hand-entered. See the full reference.

Same diameter

Other M10 threads

Nearby sizes

More metric coarse threads