M42×4.5 Thread Specifications
Complete dimensions for M42×4.5 coarse pitch thread per ISO 724. Pitch: 4.5mm (5.6 TPI equivalent).
Thread Dimensions
| Designation | M42×4.5 |
| Thread Series | ISO Metric Coarse |
| Pitch | 4.5 mm (5.6 TPI) |
| Major Diameter (d) | 42 mm (1.6535") |
| Pitch Diameter (d₂) | 39.0772 mm (1.5385") |
| Minor Diameter — External (d₁) | 36.4789 mm (1.4362") |
| Minor Diameter — Internal (D₁) | 37.1287 mm (1.4618") |
| Thread Depth | 2.4357 mm |
| Tensile Stress Area | 1120.91 mm² |
| Fundamental Triangle Height (H) | 3.8971 mm |
Tap Drill Size
Recommended tap drill: 38.0 mm
Calculated minor diameter (D₁): 37.13 mm. Closest standard metric drill: 38.0 mm.
Closest inch drill: 1-15/32" (1.4688" / 37.31 mm)
Proof Loads by Property Class
| Class | Proof Stress (MPa) | Tensile Strength (MPa) | Proof Load (kN) | Tensile Load (kN) |
|---|---|---|---|---|
| 4.6 | 225 | 400 | 252.2 | 448.4 |
| 4.8 | 310 | 420 | 347.5 | 470.8 |
| 5.8 | 380 | 520 | 425.9 | 582.9 |
| 8.8 | 580 | 800 | 650.1 | 896.7 |
| 9.8 | 650 | 900 | 728.6 | 1008.8 |
| 10.9 | 830 | 1040 | 930.4 | 1165.7 |
| 12.9 | 970 | 1220 | 1087.3 | 1367.5 |
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 M42×4.5 Dimensions Are Calculated
All dimensions on this page are calculated from ISO 724 formulas using the nominal diameter (42 mm) and pitch (4.5 mm):
- Fundamental triangle height: H = (√3/2) × P = 3.8971 mm
- Pitch diameter: d₂ = d − 0.6495 × P = 39.0772 mm
- Minor diameter (external): d₁ = d − 1.2269 × P = 36.4789 mm
- Minor diameter (internal): D₁ = d − 1.0825 × P = 37.1287 mm
- Thread depth: 5H/8 = 2.4357 mm
- Tensile stress area: Aₛ = (π/4) × ((d₂ + d₃)/2)² = 1120.91 mm²