M45×4.5 Thread Specifications
Complete dimensions for M45×4.5 coarse pitch thread per ISO 724. Pitch: 4.5mm (5.6 TPI equivalent).
Thread Dimensions
| Designation | M45×4.5 |
| Thread Series | ISO Metric Coarse |
| Pitch | 4.5 mm (5.6 TPI) |
| Major Diameter (d) | 45 mm (1.7717") |
| Pitch Diameter (d₂) | 42.0772 mm (1.6566") |
| Minor Diameter — External (d₁) | 39.4789 mm (1.5543") |
| Minor Diameter — Internal (D₁) | 40.1287 mm (1.5799") |
| Thread Depth | 2.4357 mm |
| Tensile Stress Area | 1306.0 mm² |
| Fundamental Triangle Height (H) | 3.8971 mm |
Tap Drill Size
Recommended tap drill: 40.0 mm
Calculated minor diameter (D₁): 40.13 mm. Closest standard metric drill: 40.0 mm.
Closest inch drill: 1-37/64" (1.5781" / 40.08 mm)
Proof Loads by Property Class
| Class | Proof Stress (MPa) | Tensile Strength (MPa) | Proof Load (kN) | Tensile Load (kN) |
|---|---|---|---|---|
| 4.6 | 225 | 400 | 293.9 | 522.4 |
| 4.8 | 310 | 420 | 404.9 | 548.5 |
| 5.8 | 380 | 520 | 496.3 | 679.1 |
| 8.8 | 580 | 800 | 757.5 | 1044.8 |
| 9.8 | 650 | 900 | 848.9 | 1175.4 |
| 10.9 | 830 | 1040 | 1084.0 | 1358.2 |
| 12.9 | 970 | 1220 | 1266.8 | 1593.3 |
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 M45×4.5 Dimensions Are Calculated
All dimensions on this page are calculated from ISO 724 formulas using the nominal diameter (45 mm) and pitch (4.5 mm):
- Fundamental triangle height: H = (√3/2) × P = 3.8971 mm
- Pitch diameter: d₂ = d − 0.6495 × P = 42.0772 mm
- Minor diameter (external): d₁ = d − 1.2269 × P = 39.4789 mm
- Minor diameter (internal): D₁ = d − 1.0825 × P = 40.1287 mm
- Thread depth: 5H/8 = 2.4357 mm
- Tensile stress area: Aₛ = (π/4) × ((d₂ + d₃)/2)² = 1306.0 mm²