| COUNTERSINK ANGLE | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| FASTENER LENGTH | 0.925 INCHES MINIMUM AND 0.945 INCHES MAXIMUM |
| HEAD DIAMETER | 0.518 INCHES MINIMUM AND 0.528 INCHES MAXIMUM |
| HEAD STYLE | FLAT COUNTERSUNK |
| INTERNAL DRIVE STYLE | HEXAGON |
| MATERIAL DOCUMENT AND CLASSIFICATION | MIL-S-6049 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5626 MIL SPEC 2ND MATERIAL RESPONSE OVERALL |
| MATERIAL | STEEL COMP 8740 OR STEEL COMP 4140 OVERALL |
| MINIMUM TENSILE STRENGTH | 160000 POUNDS PER SQUARE INCH |
| NOMINAL THREAD DIAMETER | 0.375 INCHES |
| SPECIAL FEATURES | 3 SPLINES 0.040 IN. WIDE BY 0.029 IN. DEEP 120 DEGREES APART, 0.112 IN.DIA HOLE FOR PLUG |
| WIDTH ACROSS FLATS | 0.312 INCHES NOMINAL |
| 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 | 0.645 INCHES NOMINAL |
| THREAD QUANTITY PER INCH | 24 |
| THREAD SERIES DESIGNATOR | UNF |