| COUNTERSINK ANGLE | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| FASTENER LENGTH | 1.355 INCHES MINIMUM AND 1.385 INCHES MAXIMUM |
| HEAD DIAMETER | 0.466 INCHES MINIMUM AND 0.518 INCHES MAXIMUM |
| HEAD STYLE | FLAT COUNTERSUNK |
| INTERNAL DRIVE STYLE | TORQUE-SET RIBBED |
| MATERIAL DOCUMENT AND CLASSIFICATION | AMS5731 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| MATERIAL | IRON ALLOY 660 OVERALL |
| MINIMUM TENSILE STRENGTH | 16000 POUNDS PER SQUARE INCH |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 28 |
| THREAD SERIES DESIGNATOR | UNIFIED NATIONAL JOINT FINE (UNJF) |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416, TYPE 2, CLASS 2 FED SPEC ALL TREATMENT RESPONSES OVERALL |
| SURFACE TREATMENT | CADMIUM AND CHROMATE OVERALL |
| THREAD CLASS | 3A |
| THREAD LENGTH | 0.363 INCHES NOMINAL |