| THREAD SERIES DESIGNATOR | UNJF |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 28 |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.403 INCHES NOMINAL |
| FASTENER LENGTH | 1.591 INCHES NOMINAL |
| MATERIAL | STEEL COMP 4140 OR |
| STEEL COMP E4340 OR |
| STEEL COMP 8740 OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | MIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR |
| MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR |
| MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM AND |
| CHROMATE OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416 TY 2 CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| MINIMUM TENSILE STRENGTH | 160000 POUNDS PER SQUARE INCH |
| HEAD STYLE | FLAT COUNTERSUNK |
| HEAD DIAMETER | 0.350 INCHES MINIMUM AND |
| 0.398 INCHES MAXIMUM |
| COUNTERSINK ANGLE | 99.0 DEGREES MINIMUM AND |
| 101.0 DEGREES MAXIMUM |
| INTERNAL DRIVE STYLE | OFFSET CRUCIFORM (TORQUE SET) |
| GRIP LENGTH | 1.365 INCHES MINIMUM AND |
| 1.385 INCHES MAXIMUM |
| GRIP DIAMETER | 0.2646 INCHES MINIMUM AND |
| 0.2651 INCHES MAXIMUM |
| SURFACE FINISH | 63.0 MICROINCHES BEARING SURFACE OF HEAD |
| 32.0 MICROINCHES GRIP |
| 32.0 MICROINCHES THREADS |
| SPECIFICATION/STANDARD DATA | 80205-NAS1581 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | BOLT, SHEAR |