M5×0.8 Thread Specifications
Complete dimensions for M5×0.8 coarse pitch thread per ISO 724. Pitch: 0.8mm (31.8 TPI equivalent).
Thread Dimensions
| Designation | M5×0.8 |
| Thread Series | ISO Metric Coarse |
| Pitch | 0.8 mm (31.8 TPI) |
| Major Diameter (d) | 5 mm (0.1969") |
| Pitch Diameter (d₂) | 4.4804 mm (0.1764") |
| Minor Diameter — External (d₁) | 4.0185 mm (0.1582") |
| Minor Diameter — Internal (D₁) | 4.134 mm (0.1628") |
| Thread Depth | 0.433 mm |
| Tensile Stress Area | 13.8 mm² |
| Fundamental Triangle Height (H) | 0.6928 mm |
Tap Drill Size
Recommended tap drill: 4.1 mm
Calculated minor diameter (D₁): 4.13 mm. Closest standard metric drill: 4.1 mm.
Closest inch drill: #20 (0.161" / 4.09 mm)
Proof Loads by Property Class
| Class | Proof Stress (MPa) | Tensile Strength (MPa) | Proof Load (kN) | Tensile Load (kN) |
|---|---|---|---|---|
| 4.6 | 225 | 400 | 3.1 | 5.5 |
| 4.8 | 310 | 420 | 4.3 | 5.8 |
| 5.8 | 380 | 520 | 5.2 | 7.2 |
| 8.8 | 580 | 800 | 8.0 | 11.0 |
| 9.8 | 650 | 900 | 9.0 | 12.4 |
| 10.9 | 830 | 1040 | 11.5 | 14.4 |
| 12.9 | 970 | 1220 | 13.4 | 16.8 |
Proof load = stress area × proof stress. Per ISO 898-1.
Related Thread Sizes
Common Applications
- Machine screws
- Electronics enclosures
- Light fixtures
- Automotive trim
How M5×0.8 Dimensions Are Calculated
All dimensions on this page are calculated from ISO 724 formulas using the nominal diameter (5 mm) and pitch (0.8 mm):
- Fundamental triangle height: H = (√3/2) × P = 0.6928 mm
- Pitch diameter: d₂ = d − 0.6495 × P = 4.4804 mm
- Minor diameter (external): d₁ = d − 1.2269 × P = 4.0185 mm
- Minor diameter (internal): D₁ = d − 1.0825 × P = 4.134 mm
- Thread depth: 5H/8 = 0.433 mm
- Tensile stress area: Aₛ = (π/4) × ((d₂ + d₃)/2)² = 13.8 mm²