1-12 UNF Thread Specifications
Complete dimensions for 1-12 UNF thread per ASME B1.1. TPI: 12, Pitch: 0.08333" (2.117 mm).
Thread Dimensions
| Designation | 1-12 UNF |
| Threads Per Inch (TPI) | 12 |
| Pitch | 0.08333" (2.117 mm) |
| Major Diameter | 1" (25.4 mm) |
| Pitch Diameter | 0.9459" (24.025 mm) |
| Minor Diameter (External) | 0.8978" (22.803 mm) |
| Minor Diameter (Internal) | 0.9098" (23.109 mm) |
| Thread Depth | 0.04511" (1.146 mm) |
| Tensile Stress Area | 0.65871 in² (425 mm²) |
Tap Drill Size
Recommended tap drill: 29/32" (0.9062" / 23.02 mm)
Calculated minor diameter (internal): 0.9098" (23.11 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 | 36,229 | 48,745 |
| Grade 5 | 85,000 | 120,000 | 55,990 | 79,045 |
| Grade 8 | 120,000 | 150,000 | 79,045 | 98,806 |
Same Size, Different Series
Common Applications
- Heavy structural, foundation bolts, large machinery
- Fine thread applications