MAN4MACHINE← All thread specs
Straight
M
ISO Metric General Purpose
The everyday 60 degree metric fastener thread. Included here because so many pipe and fitting bodies use metric ports and boss threads even when the fluid connection itself is NPT or BSP.
- Standard
- ISO 261 / ISO 724
- Flank angle
- 60° included
- Sealing
- None -- a fastening thread, sealed (if at all) by a separate gasket, O-ring, or thread sealant.
Thread profile
A 60° included flank angle with a flat-truncated crest and root -- the single fastest way to tell a Unified/American pipe thread from the other family by eye.
Cut straight: the pitch diameter is constant along the full thread length, with no taper.
Size chart
| Nominal | TPI | Pitch | Major Ø | Pitch Ø | Minor Ø | Tap drill |
|---|---|---|---|---|---|---|
| M3 | 50.80 | 0.0197" | 0.1181" | 0.1053" | 0.0925" | #39 (0.0989") |
| M4 | 36.29 | 0.0276" | 0.1575" | 0.1396" | 0.1217" | #30 (0.1306") |
| M5 | 31.75 | 0.0315" | 0.1969" | 0.1764" | 0.1559" | #19 (0.1662") |
| M6 | 25.40 | 0.0394" | 0.2362" | 0.2106" | 0.1851" | #8 (0.1979") |
| M8 | 20.32 | 0.0492" | 0.3150" | 0.2830" | 0.2510" | H (0.2670") |
| M10 | 16.93 | 0.0591" | 0.3937" | 0.3553" | 0.3170" | R (0.3362") |
| M12 | 14.51 | 0.0689" | 0.4724" | 0.4277" | 0.3829" | 13/32" (0.4053") |
| M16 | 12.70 | 0.0787" | 0.6299" | 0.5788" | 0.5276" | 35/64" (0.5532") |
| M20 | 10.16 | 0.0984" | 0.7874" | 0.7235" | 0.6595" | 11/16" (0.6915") |
| M24 | 8.47 | 0.1181" | 0.9449" | 0.8682" | 0.7915" | 53/64" (0.8298") |
| M30 | 7.26 | 0.1378" | 1.1811" | 1.0916" | 1.0021" | 1-3/64" (1.0469") |
| M36 | 6.35 | 0.1575" | 1.4173" | 1.3150" | 1.2127" | 1-17/64" (1.2639") |
Tap drill calculator
Calculated live
Tap drill#390.0989" calculated · #39 (0.0989") nearest standard
- Pitch
- 0.0197"
- Pitch diameter (basic)
- 0.1053"
- Minor diameter (basic)
- 0.0925"
- Clearance drill (normal)
- #25 (0.1494")
Comparing against another standard? Open the universal calculator →