M1.4×0.3 Thread Specifications
Complete dimensions for M1.4×0.3 coarse pitch thread per ISO 724. Pitch: 0.3mm (84.7 TPI equivalent).
Thread Dimensions
| Designation | M1.4×0.3 |
| Thread Series | ISO Metric Coarse |
| Pitch | 0.3 mm (84.7 TPI) |
| Major Diameter (d) | 1.4 mm (0.0551") |
| Pitch Diameter (d₂) | 1.2051 mm (0.0474") |
| Minor Diameter — External (d₁) | 1.0319 mm (0.0406") |
| Minor Diameter — Internal (D₁) | 1.0753 mm (0.0423") |
| Thread Depth | 0.1624 mm |
| Tensile Stress Area | 0.94 mm² |
| Fundamental Triangle Height (H) | 0.2598 mm |
Tap Drill Size
Recommended tap drill: 1.1 mm
Calculated minor diameter (D₁): 1.08 mm. Closest standard metric drill: 1.1 mm.
Closest inch drill: #57 (0.043" / 1.09 mm)
Proof Loads by Property Class
| Class | Proof Stress (MPa) | Tensile Strength (MPa) | Proof Load (kN) | Tensile Load (kN) |
|---|---|---|---|---|
| 4.6 | 225 | 400 | 0.2 | 0.4 |
| 4.8 | 310 | 420 | 0.3 | 0.4 |
| 5.8 | 380 | 520 | 0.4 | 0.5 |
| 8.8 | 580 | 800 | 0.5 | 0.8 |
| 9.8 | 650 | 900 | 0.6 | 0.8 |
| 10.9 | 830 | 1040 | 0.8 | 1.0 |
| 12.9 | 970 | 1220 | 0.9 | 1.1 |
Proof load = stress area × proof stress. Per ISO 898-1.
Common Applications
- Electronics
- Instrument screws
- Watch mechanisms
- Small fasteners
How M1.4×0.3 Dimensions Are Calculated
All dimensions on this page are calculated from ISO 724 formulas using the nominal diameter (1.4 mm) and pitch (0.3 mm):
- Fundamental triangle height: H = (√3/2) × P = 0.2598 mm
- Pitch diameter: d₂ = d − 0.6495 × P = 1.2051 mm
- Minor diameter (external): d₁ = d − 1.2269 × P = 1.0319 mm
- Minor diameter (internal): D₁ = d − 1.0825 × P = 1.0753 mm
- Thread depth: 5H/8 = 0.1624 mm
- Tensile stress area: Aₛ = (π/4) × ((d₂ + d₃)/2)² = 0.94 mm²