#8-36 UNF Thread Specifications
Complete dimensions for #8-36 UNF (Unified National Fine) thread per ASME B1.1. TPI: 36, Pitch: 0.02778" (0.706 mm).
Thread Dimensions
| Designation | #8-36 UNF |
| Threads Per Inch (TPI) | 36 |
| Pitch | 0.02778" (0.706 mm) |
| Major Diameter | 0.164" (4.166 mm) |
| Pitch Diameter | 0.146" (3.707 mm) |
| Minor Diameter (External) | 0.1299" (3.3 mm) |
| Minor Diameter (Internal) | 0.1339" (3.402 mm) |
| Thread Depth | 0.01504" (0.382 mm) |
| Tensile Stress Area | 0.01473 in² (9.5 mm²) |
Tap Drill Size
Recommended tap drill: #29 (0.136" / 3.45 mm)
Calculated minor diameter (internal): 0.1339" (3.4 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 | 810 | 1,090 |
| Grade 5 | 85,000 | 120,000 | 1,252 | 1,768 |
| Grade 8 | 120,000 | 150,000 | 1,768 | 2,210 |
Same Size, Different Series
Common Applications
- Electronics
- Instrument screws
- Precision assemblies
- Avionics