3/4-10 UNC Thread Specifications
Complete dimensions for 3/4-10 UNC (Unified National Coarse) thread per ASME B1.1. TPI: 10, Pitch: 0.1" (2.54 mm).
Thread Dimensions
| Designation | 3/4-10 UNC |
| Threads Per Inch (TPI) | 10 |
| Pitch | 0.1" (2.54 mm) |
| Major Diameter | 0.75" (19.05 mm) |
| Pitch Diameter | 0.6851" (17.4 mm) |
| Minor Diameter (External) | 0.6273" (15.934 mm) |
| Minor Diameter (Internal) | 0.6418" (16.3 mm) |
| Thread Depth | 0.05413" (1.375 mm) |
| Tensile Stress Area | 0.33446 in² (215.8 mm²) |
Tap Drill Size
Recommended tap drill: 41/64" (0.6406" / 16.27 mm)
Calculated minor diameter (internal): 0.6418" (16.3 mm)
Proof Loads by SAE Grade
| Grade | Proof Stress (psi) | Tensile Strength (psi) | Proof Load (lbf) | Tensile Load (lbf) |
|---|---|---|---|---|
| Grade 2 | 55,000 | 74,000 | 18,395 | 24,750 |
| Grade 5 | 85,000 | 120,000 | 28,429 | 40,135 |
| Grade 8 | 120,000 | 150,000 | 40,135 | 50,169 |
Same Size, Different Series
Common Applications
- Structural steel, bridge connections, heavy equipment
- Coarse thread applications