THREAD SERIES DESIGNATOR | UNC |
NOMINAL THREAD DIAMETER | 0.250 INCHES |
THREAD QUANTITY PER INCH | 20 |
THREAD CLASS | 3A |
THREAD DIRECTION | RIGHT-HAND |
THREAD LENGTH | 0.775 INCHES MAXIMUM |
FASTENER LENGTH | 0.875 INCHES NOMINAL |
MATERIAL | PLASTIC POLYAMIDE LOCKING FEATURE |
| STEEL UNS K03104 FASTENER |
MATERIAL DOCUMENT AND CLASSIFICATION | MIL-F-18240 MIL SPEC SINGLE MATERIAL RESPONSE LOCKING FEATURE |
| ASTM A574 ASSN STD SINGLE MATERIAL RESPONSE FASTENER |
SURFACE TREATMENT | ZINC AND |
| CHROMATE FASTENER |
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | ASTM B633, TYPE 2 FED SPEC ALL TREATMENT RESPONSES FASTENER |
HARDNESS RATING | 38.0 ROCKWELL C MINIMUM AND |
| 45.0 ROCKWELL C MAXIMUM OVERALL |
MINIMUM TENSILE STRENGTH | 170000 POUNDS PER SQUARE INCH |
MINIMUM YIELD STRENGTH | 150000 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 |
LOCKING FEATURE | PATCH THREADS |
SURFACE FINISH | 63.0 MICROINCHES BEARING SURFACE OF HEAD |
| 63.0 MICROINCHES GRIP |
| 32.0 MICROINCHES THREADS |