M8×1.0 Thread Specifications
Complete dimensions for M8×1.0 fine pitch thread per ISO 724. Pitch: 1.0mm (25.4 TPI equivalent).
Thread Dimensions
| Designation | M8×1.0 |
| Thread Series | ISO Metric Fine |
| Pitch | 1.0 mm (25.4 TPI) |
| Major Diameter (d) | 8 mm (0.315") |
| Pitch Diameter (d₂) | 7.3505 mm (0.2894") |
| Minor Diameter — External (d₁) | 6.7731 mm (0.2667") |
| Minor Diameter — Internal (D₁) | 6.9175 mm (0.2723") |
| Thread Depth | 0.5413 mm |
| Tensile Stress Area | 38.37 mm² |
| Fundamental Triangle Height (H) | 0.866 mm |
Tap Drill Size
Recommended tap drill: 7.0 mm
Calculated minor diameter (D₁): 6.92 mm. Closest standard metric drill: 7.0 mm.
Closest inch drill: I (0.272" / 6.91 mm)
Proof Loads by Property Class
| Class | Proof Stress (MPa) | Tensile Strength (MPa) | Proof Load (kN) | Tensile Load (kN) |
|---|---|---|---|---|
| 4.6 | 225 | 400 | 8.6 | 15.3 |
| 4.8 | 310 | 420 | 11.9 | 16.1 |
| 5.8 | 380 | 520 | 14.6 | 20.0 |
| 8.8 | 580 | 800 | 22.3 | 30.7 |
| 9.8 | 650 | 900 | 24.9 | 34.5 |
| 10.9 | 830 | 1040 | 31.8 | 39.9 |
| 12.9 | 970 | 1220 | 37.2 | 46.8 |
Proof load = stress area × proof stress. Per ISO 898-1.
Related Thread Sizes
Common Applications
- Automotive engine components
- Precision machinery
- Vibration-prone joints
- Cylinder head bolts
How M8×1.0 Dimensions Are Calculated
All dimensions on this page are calculated from ISO 724 formulas using the nominal diameter (8 mm) and pitch (1.0 mm):
- Fundamental triangle height: H = (√3/2) × P = 0.866 mm
- Pitch diameter: d₂ = d − 0.6495 × P = 7.3505 mm
- Minor diameter (external): d₁ = d − 1.2269 × P = 6.7731 mm
- Minor diameter (internal): D₁ = d − 1.0825 × P = 6.9175 mm
- Thread depth: 5H/8 = 0.5413 mm
- Tensile stress area: Aₛ = (π/4) × ((d₂ + d₃)/2)² = 38.37 mm²