| THREAD SERIES | UNJF |
| NOMINAL THREAD SIZE | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 28 |
| THREAD CLASS | 3B |
| MATERIAL | STEEL CORROSION RESISTING OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | AMS 5731 OR AMS 5734 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | AMS 2411 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| HARDNESS RATING | HRC 37-45 |
| NUT STYLE | DOUBLE HEXAGON |
| NUT HEIGHT | 0.307 INCHES MINIMUM AND |
| 0.322 INCHES MAXIMUM |
| WIDTH ACROSS FLATS | 0.430 INCHES NOMINAL |
| SPECIAL FEATURES | FINISH: SILVER PLATE PER AMS 2411; SILVER PLATE ONLY ON THE THREADS WITH OPTIONAL COVERAGE ON COUNTERSINK. DIMENTIONS APPLY AFTER PLATING. UPPER THREADED PORTION DEFORMED FOR LOCKING FEATURE, TOOL MARKS AND DISTORTION ARE PERMISSIBLE IN LOCKING AREA. |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | NUT, SELF-LOCKING, 12 POINT, REDUCED HEIGHT, SILVER PLATE, UNS S66286 |