| COUNTERSINK ANGLE | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| FASTENER LENGTH | 1.020 INCHES NOMINAL |
| GRIP LENGTH | 0.625 INCHES NOMINAL |
| HEAD STYLE | FLUSH COUNTERSUNK |
| HEAD MAJOR DIAMETER | 0.5006 INCHES MINIMUM AND 0.5086 INCHES MAXIMUM |
| LUBRICATION | CETYL ALCOHOL |
| MATERIAL DOCUMENT AND CLASSIFICATION | AMS 5731 FED SPEC SINGLE MATERIAL RESPONSE OR AMS 5737 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| MATERIAL | IRON ALLOY 660 OVERALL |
| PROPRIETARY CHARACTERISTICS | PACS |
| NOMINAL THREAD SIZE | 0.250 INCHES |
| SHANK DIAMETER | 0.2481 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM |
| SHANK STYLE | PIN-RIVET, STRAIGHT, THREADED |
| WIDTH BETWEEN FLATS | 0.0947 INCHES MINIMUM AND 0.0967 INCHES MAXIMUM |
| SURFACE TREATMENT | ALUMINUM OVERALL |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD QUANTITY PER INCH | 28 |
| THREAD SERIES DESIGNATOR | UNJF |