5/16-24 UNF Thread Specifications
Complete dimensions for 5/16-24 UNF (Unified National Fine) thread per ASME B1.1. TPI: 24, Pitch: 0.04167" (1.058 mm).
Thread Dimensions
| Designation | 5/16-24 UNF |
| Threads Per Inch (TPI) | 24 |
| Pitch | 0.04167" (1.058 mm) |
| Major Diameter | 0.3125" (7.938 mm) |
| Pitch Diameter | 0.2854" (7.25 mm) |
| Minor Diameter (External) | 0.2614" (6.639 mm) |
| Minor Diameter (Internal) | 0.2674" (6.792 mm) |
| Thread Depth | 0.02255" (0.573 mm) |
| Tensile Stress Area | 0.05807 in² (37.5 mm²) |
Tap Drill Size
Recommended tap drill: H (0.266" / 6.76 mm)
Calculated minor diameter (internal): 0.2674" (6.79 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 | 3,194 | 4,297 |
| Grade 5 | 85,000 | 120,000 | 4,936 | 6,968 |
| Grade 8 | 120,000 | 150,000 | 6,968 | 8,710 |
Same Size, Different Series
Common Applications
- Machinery, automotive accessories, medium-duty brackets
- Fine thread applications