| COUNTERBORE DIAMETER | 0.290 INCHES MINIMUM AND 0.300 INCHES MAXIMUM NUT |
| MATERIAL DOCUMENT AND CLASSIFICATION | ASTM A581 ASSN STD ALL MATERIAL RESPONSES OVERALL |
| MATERIAL | STEEL COMP 203EZ OR STEEL COMP 303 PLUS X OR STEEL COMP 416 PLUS X OR STEEL COMP 303 OR STEEL COMP 303PB OR STEEL COMP 303SE OR STEEL COMP 416 OR STEEL COMP 416SE OR STEEL COMP 430F OR STEEL COMP 430FSE OVERALL |
| NOMINAL THREAD SIZE | 0.250 INCHES |
| NUT COUNTERBORE DEPTH | 0.307 INCHES MINIMUM AND 0.317 INCHES MAXIMUM NUT |
| NUT DIAMETER | 0.497 INCHES MINIMUM AND 0.503 INCHES MAXIMUM |
| NUT HEIGHT | 0.428 INCHES MINIMUM AND 0.448 INCHES MAXIMUM |
| NUT STYLE | SPLINE |
| PILOT DIAMETER | 0.366 INCHES MINIMUM AND 0.369 INCHES MAXIMUM |
| PILOT LENGTH | 0.245 INCHES MINIMUM AND 0.255 INCHES MAXIMUM |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | PASSIVATE OVERALL |
| THREAD CLASS | 2B |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD QUANTITY PER INCH | 28 |
| THREAD SERIES | UNF |