#1-64 UNC Thread Specifications
Complete dimensions for #1-64 UNC (Unified National Coarse) thread per ASME B1.1. TPI: 64, Pitch: 0.01562" (0.397 mm).
Thread Dimensions
| Designation | #1-64 UNC |
| Threads Per Inch (TPI) | 64 |
| Pitch | 0.01562" (0.397 mm) |
| Major Diameter | 0.073" (1.854 mm) |
| Pitch Diameter | 0.0629" (1.596 mm) |
| Minor Diameter (External) | 0.0538" (1.367 mm) |
| Minor Diameter (Internal) | 0.0561" (1.425 mm) |
| Thread Depth | 0.00846" (0.215 mm) |
| Tensile Stress Area | 0.00262 in² (1.7 mm²) |
Tap Drill Size
Recommended tap drill: #54 (0.055" / 1.4 mm)
Calculated minor diameter (internal): 0.0561" (1.43 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 | 144 | 194 |
| Grade 5 | 85,000 | 120,000 | 223 | 314 |
| Grade 8 | 120,000 | 150,000 | 314 | 393 |
Same Size, Different Series
Common Applications
- Machine screws
- Electrical covers
- Small appliances
- Sheet metal