1-3/16-18 UNEF Thread Specifications
Complete dimensions for 1-3/16-18 UNEF (Unified National Extra Fine) thread per ASME B1.1. TPI: 18, Pitch: 0.05556" (1.411 mm).
Thread Dimensions
| Designation | 1-3/16-18 UNEF |
| Threads Per Inch (TPI) | 18 |
| Pitch | 0.05556" (1.411 mm) |
| Major Diameter | 1.1875" (30.162 mm) |
| Pitch Diameter | 1.1514" (29.246 mm) |
| Minor Diameter (External) | 1.1193" (28.431 mm) |
| Minor Diameter (Internal) | 1.1274" (28.635 mm) |
| Thread Depth | 0.03007" (0.764 mm) |
| Tensile Stress Area | 1.00887 in² (650.9 mm²) |
Tap Drill Size
Recommended tap drill: 1-9/64" (1.1406" / 28.97 mm)
Calculated minor diameter (internal): 1.1274" (28.64 mm)
Proof Loads by SAE Grade
| Grade | Proof Stress (psi) | Tensile Strength (psi) | Proof Load (lbf) | Tensile Load (lbf) |
|---|---|---|---|---|
| Grade 2 | 33,000 | 60,000 | 33,293 | 60,532 |
| Grade 5 | 74,000 | 105,000 | 74,657 | 105,932 |
| Grade 8 | 120,000 | 150,000 | 121,065 | 151,331 |
Common Applications
- Precision assemblies
- Thin-wall tubing
- Aerospace fittings