| COUNTERSINK ANGLE | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| FASTENER LENGTH | 0.638 INCHES MINIMUM AND 0.668 INCHES MAXIMUM |
| GRIP LENGTH | 0.240 INCHES MINIMUM AND 0.260 INCHES MAXIMUM |
| GRIP DIAMETER | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM |
| HEAD DIAMETER | 0.3504 INCHES MINIMUM AND 0.3988 INCHES MAXIMUM |
| HEAD STYLE | FLAT COUNTERSUNK |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| NONSTANDARD THREAD PITCH DIAMETER | +0.2157/+0.2195 INCHES |
| INTERNAL DRIVE STYLE | OFFSET CRUCIFORM (TORQUE SET) |
| MATERIAL DOCUMENT AND CLASSIFICATION | AMS 5731 ASSN STD SINGLE MATERIAL RESPONSE OVERALL OR AMS 5732 ASSN STD SINGLE MATERIAL RESPONSE OVERALL OR AMS 4737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| MATERIAL | IRON ALLOY 660 OVERALL |
| MINIMUM TENSILE STRENGTH | 160000 POUNDS PER SQUARE INCH |
| SPECIAL FEATURES | INTERNAL DRIVE RIBBED |
| THREAD QUANTITY PER INCH | 28 |
| THREAD SERIES DESIGNATOR | UNJF |
| SPECIFICATION/STANDARD DATA | 80205-NAS1581 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| SURFACE FINISH | 32.0 MICROINCHES GRIP |
| SURFACE FINISH | 32.0 MICROINCHES THREADS |
| SURFACE TREATMENT | CADMIUM OVERALL |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.378 INCHES MINIMUM AND 0.428 INCHES MAXIMUM |