| BEARING SURFACE TYPE | CHAMFERED |
| COUNTERSINK ANGLE | 109.0 DEGREES MINIMUM AND 111.0 DEGREES MAXIMUM NUT |
| MATERIAL DOCUMENT AND CLASSIFICATION | AMS5525 AEROSPACE MATERIAL SPEC STD ALL MATERIAL RESPONSES OR AMS5732 AEROSPACE MATERIAL SPEC STD ALL MATERIAL RESPONSES OR AMS5737 AEROSPACE MATERIAL SPEC STD ALL MATERIAL RESPONSES OVERALL |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | NUT, JAM, DRILLED AND UNDRILLED |
| MATERIAL | STEEL CORROSION RESISTING OVERALL |
| NOMINAL THREAD SIZE | 0.2500 INCHES |
| NUT HEIGHT | 0.178 INCHES MINIMUM AND 0.198 INCHES MAXIMUM |
| NUT STYLE | HEXAGON |
| SPECIAL FEATURES | MATERIAL: CRES, A286 (UNS S66286) PER AMS5525, AMS5732, OR AMS5737. FINISH: PASSIVATE PER AMS2700, METHOD 1, CLASS 4 (CODE C). CRES, 150 KSI MIN TENSILE STRENGTH. CODE U = UNDRILLED. THREAD PER AS8879. |
| SPECIFICATION/STANDARD DATA | 80205-NAS509 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | AMS2700, METHOD 1, CLASS 4 INTERNATIONAL STD/SPEC ALL TREATMENT RESPONSES OVERALL |
| SURFACE TREATMENT | PASSIVATE OVERALL |
| THREAD CLASS | 2B |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD QUANTITY PER INCH | 28 |
| THREAD SERIES | UNIFIED NATIONAL JOINT FINE (UNJF) |
| WIDTH ACROSS FLATS | 0.428 INCHES MINIMUM AND 0.448 INCHES MAXIMUM |