1/2-13 UNC Thread Specifications
Complete dimensions for 1/2-13 UNC (Unified National Coarse) thread per ASME B1.1. TPI: 13, Pitch: 0.07692" (1.954 mm).
Thread Dimensions
| Designation | 1/2-13 UNC |
| Threads Per Inch (TPI) | 13 |
| Pitch | 0.07692" (1.954 mm) |
| Major Diameter | 0.5" (12.7 mm) |
| Pitch Diameter | 0.45" (11.431 mm) |
| Minor Diameter (External) | 0.4056" (10.303 mm) |
| Minor Diameter (Internal) | 0.4167" (10.585 mm) |
| Thread Depth | 0.04164" (1.058 mm) |
| Tensile Stress Area | 0.14190 in² (91.5 mm²) |
Tap Drill Size
Recommended tap drill: Z (0.413" / 10.49 mm)
Calculated minor diameter (internal): 0.4167" (10.59 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 | 7,804 | 10,501 |
| Grade 5 | 85,000 | 120,000 | 12,062 | 17,028 |
| Grade 8 | 120,000 | 150,000 | 17,028 | 21,285 |
Same Size, Different Series
Common Applications
- Structural steel, automotive suspension, heavy machinery
- Coarse thread applications