M7 × 1.0 — Tap Drill, Dimensions & Torque

Profile

Thread form & key diameters

Dimensions

Designation	M7 × 1.0
Major (outside) diameter	7 mm · 0.2756"
Pitch	1 mm · 25.4 TPI
Pitch diameter	6.351 mm · 0.25"
Minor diameter (external)	5.773 mm · 0.2273"
Minor diameter (internal)	5.918 mm · 0.233"
Recommended tap drill	6 mm · ≈77% thread
Clearance hole	Close 7.4 · Normal 7.6 · Loose 8 mm
Hex head (across flats)	11 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 / class	Stress area	Preload	Torque
Class 8.8	28.9 mm²	12.55 kN	17.6 N·m
Class 10.9	28.9 mm²	17.97 kN	25.2 N·m
Class 12.9	28.9 mm²	21 kN	29.4 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 M7 × 1.0?

For a M7 × 1.0 thread, drill the hole with a 6 mm tap drill (6 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 7 mm and a pitch of 1 mm (25.4 TPI).

To pass a M7 × 1.0 bolt through a part rather than thread it, use a clearance hole: Close 7.4 · Normal 7.6 · Loose 8 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 M7 threads

M7 × 0.75Tap 6.25 mmØ 7 mm · pitch 0.75 mm

Nearby sizes

More metric coarse threads

M6 × 1.0Tap 5 mmØ 6 mm · pitch 1 mm M8 × 1.25Tap 6.75 mmØ 8 mm · pitch 1.25 mm M5 × 0.8Tap 4.2 mmØ 5 mm · pitch 0.8 mm M4 × 0.7Tap 3.3 mmØ 4 mm · pitch 0.7 mm M10 × 1.5Tap 8.5 mmØ 10 mm · pitch 1.5 mm M3.5 × 0.6Tap 2.9 mmØ 3.5 mm · pitch 0.6 mm M3 × 0.5Tap 2.5 mmØ 3 mm · pitch 0.5 mm M2.5 × 0.45Tap 2.05 mmØ 2.5 mm · pitch 0.45 mm