M39×1.5 Thread Specifications
Complete dimensions for M39×1.5 fine pitch thread per ISO 724. Pitch: 1.5mm (16.9 TPI equivalent).
Thread Dimensions
| Designation | M39×1.5 |
| Thread Series | ISO Metric Fine |
| Pitch | 1.5 mm (16.9 TPI) |
| Major Diameter (d) | 39 mm (1.5354") |
| Pitch Diameter (d₂) | 38.0258 mm (1.4971") |
| Minor Diameter — External (d₁) | 37.1596 mm (1.463") |
| Minor Diameter — Internal (D₁) | 37.3762 mm (1.4715") |
| Thread Depth | 0.8119 mm |
| Tensile Stress Area | 1103.55 mm² |
| Fundamental Triangle Height (H) | 1.299 mm |
Tap Drill Size
Recommended tap drill: 38.0 mm
Calculated minor diameter (D₁): 37.38 mm. Closest standard metric drill: 38.0 mm.
Closest inch drill: 1/1" (1.0" / 25.4 mm)
Proof Loads by Property Class
| Class | Proof Stress (MPa) | Tensile Strength (MPa) | Proof Load (kN) | Tensile Load (kN) |
|---|---|---|---|---|
| 4.6 | 225 | 400 | 248.3 | 441.4 |
| 4.8 | 310 | 420 | 342.1 | 463.5 |
| 5.8 | 380 | 520 | 419.3 | 573.8 |
| 8.8 | 580 | 800 | 640.1 | 882.8 |
| 9.8 | 650 | 900 | 717.3 | 993.2 |
| 10.9 | 830 | 1040 | 915.9 | 1147.7 |
| 12.9 | 970 | 1220 | 1070.4 | 1346.3 |
Proof load = stress area × proof stress. Per ISO 898-1.
Related Thread Sizes
Common Applications
- Structural steel
- Bridge construction
- Heavy industrial equipment
- Foundation bolts
How M39×1.5 Dimensions Are Calculated
All dimensions on this page are calculated from ISO 724 formulas using the nominal diameter (39 mm) and pitch (1.5 mm):
- Fundamental triangle height: H = (√3/2) × P = 1.299 mm
- Pitch diameter: d₂ = d − 0.6495 × P = 38.0258 mm
- Minor diameter (external): d₁ = d − 1.2269 × P = 37.1596 mm
- Minor diameter (internal): D₁ = d − 1.0825 × P = 37.3762 mm
- Thread depth: 5H/8 = 0.8119 mm
- Tensile stress area: Aₛ = (π/4) × ((d₂ + d₃)/2)² = 1103.55 mm²