| THREAD SERIES DESIGNATOR | UNC |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 20 |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.500 INCHES MAXIMUM |
| FASTENER LENGTH | 0.500 INCHES NOMINAL |
| MATERIAL | PLASTIC POLYAMIDE LOCKING FEATURE |
| STEEL UNS K03104 FASTENER |
| MATERIAL DOCUMENT AND CLASSIFICATION | ASTM A574 ASSN STD SINGLE MATERIAL RESPONSE FASTENER |
| SURFACE TREATMENT | ZINC AND |
| CHROMATE FASTENER |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | ASTM B633 ASSN STD SINGLE TREATMENT RESPONSE OR |
| MIL-C-81562 TY 2 CL 6 MIL SPEC SINGLE TREATMENT RESPONSE FASTENER |
| HARDNESS RATING | 39.0 ROCKWELL C MINIMUM AND |
| 45.0 ROCKWELL C MAXIMUM FASTENER |
| MINIMUM TENSILE STRENGTH | 180000 POUNDS PER SQUARE INCH |
| HEAD STYLE | FLAT CHAMFER |
| HEAD DIAMETER | 0.365 INCHES MINIMUM AND |
| 0.375 INCHES MAXIMUM |
| HEAD HEIGHT | 0.244 INCHES MINIMUM AND |
| 0.250 INCHES MAXIMUM |
| INTERNAL DRIVE STYLE | HEXAGON |
| WIDTH ACROSS FLATS | 0.188 INCHES NOMINAL |
| SPECIAL FEATURES | MIN. OF 12 PERCENT ELONGATION IN A LENGTH OF FOUR DIAMETERS. |
| NONDEFINITIVE SPEC/STD DATA | 6 TYPE |
| SPEC/STD CONTROLLING DATA | |
| MANUFACTURERS CODE | 81348 |
| NON-DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | FF-S-86 |