Metric fine
Tap drill 28 mm for a M30 × 2.0 thread — major Ø 30 mm, pitch 2 mm (12.7 TPI).
Profile
| Designation | M30 × 2.0 |
|---|---|
| Major (outside) diameter | 30 mm · 1.1811" |
| Pitch | 2 mm · 12.7 TPI |
| Pitch diameter | 28.701 mm · 1.13" |
| Minor diameter (external) | 27.546 mm · 1.0845" |
| Minor diameter (internal) | 27.835 mm · 1.0959" |
| Recommended tap drill | 28 mm · ≈77% thread |
| Clearance hole | Close 31 · Normal 33 · Loose 35 mm |
| Hex head (across flats) | 46 mm |
| Socket key (across flats) | 22 mm |
ISO 273 clearance holes (fine / medium / coarse).
Target preload is 75% of proof load; torque is estimated from T = K · F · d.
| Grade / class | Stress area | Preload | Torque |
|---|---|---|---|
| Class 8.8 | 621.2 mm² | 270.22 kN | 1621.3 N·m |
| Class 10.9 | 621.2 mm² | 386.7 kN | 2320.2 N·m |
| Class 12.9 | 621.2 mm² | 451.92 kN | 2711.5 N·m |
For a M30 × 2.0 thread, drill the hole with a 28 mm tap drill (28 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 30 mm and a pitch of 2 mm (12.7 TPI).
To pass a M30 × 2.0 bolt through a part rather than thread it, use a clearance hole: Close 31 · Normal 33 · Loose 35 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
Nearby sizes