| COUNTERBORE DIAMETER | 0.253 INCHES MINIMUM AND 0.263 INCHES MAXIMUM NUT |
| COUNTERSINK ANGLE | 120.0 DEGREES NOMINAL NUT |
| FEATURES PROVIDED | CASEHARDENED |
| LOCKING FEATURE | PREVAILING TORQUE ALL METAL DESIGN |
| MATERIAL DOCUMENT AND CLASSIFICATION | QQ-S-637 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| MATERIAL | STEEL COMP 1211 OR STEEL COMP 1212 OR STEEL COMP 1213 OR STEEL COMP 12L14 OVERALL |
| NOMINAL THREAD SIZE | 0.250 INCHES |
| NUT COUNTERBORE DEPTH | 0.015 INCHES MINIMUM AND 0.021 INCHES MAXIMUM NUT |
| NUT HEIGHT | 0.426 INCHES MINIMUM AND 0.438 INCHES MAXIMUM |
| NUT DIAMETER | 0.869 INCHES MINIMUM AND 0.879 INCHES MAXIMUM |
| NUT STYLE | SPLINE |
| PILOT DIAMETER | 0.717 INCHES MINIMUM AND 0.725 INCHES MAXIMUM |
| PILOT LENGTH | 0.220 INCHES MINIMUM AND 0.225 INCHES MAXIMUM |
| SURFACE TREATMENT | CADMIUM AND CHROMATE OVERALL |
| THREAD CLASS | 2B |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD QUANTITY PER INCH | 20 |
| THREAD SERIES | UNIFIED NATIONAL COARSE (UNC) |