Metric fine
Tap drill 14.5 mm for a M16 × 1.5 thread — major Ø 16 mm, pitch 1.5 mm (16.93 TPI).
Profile
| Designation | M16 × 1.5 |
|---|---|
| Major (outside) diameter | 16 mm · 0.6299" |
| Pitch | 1.5 mm · 16.93 TPI |
| Pitch diameter | 15.026 mm · 0.5916" |
| Minor diameter (external) | 14.16 mm · 0.5575" |
| Minor diameter (internal) | 14.376 mm · 0.566" |
| Recommended tap drill | 14.5 mm · ≈77% thread |
| Clearance hole | Close 17 · Normal 17.5 · Loose 18.5 mm |
| Hex head (across flats) | 24 mm |
| Socket key (across flats) | 14 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 | 167.2 mm² | 72.75 kN | 232.8 N·m |
| Class 10.9 | 167.2 mm² | 104.11 kN | 333.2 N·m |
| Class 12.9 | 167.2 mm² | 121.67 kN | 389.4 N·m |
For a M16 × 1.5 thread, drill the hole with a 14.5 mm tap drill (14.5 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 16 mm and a pitch of 1.5 mm (16.93 TPI).
To pass a M16 × 1.5 bolt through a part rather than thread it, use a clearance hole: Close 17 · Normal 17.5 · Loose 18.5 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