#4-48 UNF Thread Specifications
Complete dimensions for #4-48 UNF (Unified National Fine) thread per ASME B1.1. TPI: 48, Pitch: 0.02083" (0.529 mm).
Thread Dimensions
| Designation | #4-48 UNF |
| Threads Per Inch (TPI) | 48 |
| Pitch | 0.02083" (0.529 mm) |
| Major Diameter | 0.112" (2.845 mm) |
| Pitch Diameter | 0.0985" (2.501 mm) |
| Minor Diameter (External) | 0.0864" (2.196 mm) |
| Minor Diameter (Internal) | 0.0894" (2.272 mm) |
| Thread Depth | 0.01128" (0.286 mm) |
| Tensile Stress Area | 0.00660 in² (4.3 mm²) |
Tap Drill Size
Recommended tap drill: #43 (0.089" / 2.26 mm)
Calculated minor diameter (internal): 0.0894" (2.27 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 | 363 | 488 |
| Grade 5 | 85,000 | 120,000 | 561 | 792 |
| Grade 8 | 120,000 | 150,000 | 792 | 990 |
Same Size, Different Series
Common Applications
- Electronics
- Instrument screws
- Precision assemblies
- Avionics