- Hex Head Airframe Bolts come in either drilled or undrilled shank versions
- Threads are pressed into the steel, not cut, thus maintaining strength throughout the entire shank
- The surface under the head of AN bolts is designed to be a bearing surface to reduce non-uniform stress as the bolt is torqued thus reducing premature fatigue
| Type | Hex Head Airframe Bolt |
| Style | AN4 |
| Size | 1/4"-28 |
| Length | 2-1/32" |
| Material | Steel |
| Dia. Max | 0.249 |
| Dia. Min | 0.246 |
| Head Style | Hex Head, Drilled |
| Wrench Size | 7/16" |
| Shank Hole | None |
| Head Hole | 0.046 |
| Min Tensile Strength | 125,000 psi |
| Grip | 1-9/16 |
| Finish Spec | QQ-P-416, Type II, Grade/Class 3 |
| Compatible Washer | AN960-416 or AN970-4 |
| Compatible Nut | AN365-428 |
| Fits Cotter Pin | AN380-2-2/MS24655-132 or longer |
| Thread Type | UNF-3A |
| Length | 0.469 |
| AN Part No. | AN4H-20A |
