| THREAD SERIES DESIGNATOR | UNC |
| NOMINAL THREAD DIAMETER | 0.312 INCHES |
| THREAD QUANTITY PER INCH | 18 |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.639 INCHES NOMINAL |
| FASTENER LENGTH | 0.750 INCHES NOMINAL |
| MATERIAL | STEEL OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | SAE GRADE 2 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM OR |
| ZINC OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | AMS2400-1 ASSN STD 1ST TREATMENT RESPONSE OR |
| AMS2402-1 ASSN STD 2ND TREATMENT RESPONSE OVERALL |
| HARDNESS RATING | 80.0 ROCKWELL B MINIMUM AND |
| 100.0 ROCKWELL B MAXIMUM OVERALL |
| MINIMUM TENSILE STRENGTH | 74000 POUNDS PER SQUARE INCH |
| MINIMUM YIELD STRENGTH | 57000 POUNDS PER SQUARE INCH |
| HEAD STYLE | HEXAGON |
| HEAD HEIGHT | 0.208 INCHES MINIMUM AND |
| 0.230 INCHES MAXIMUM |
| WIDTH BETWEEN FLATS | 0.489 INCHES MINIMUM AND |
| 0.500 INCHES MAXIMUM |
| INTERNAL DRIVE STYLE | SLOT |
| WASHER QUANTITY | 1 |
| PRIMARY WASHER STYLE | FLAT EXTERNAL TEETH |
| PRIMARY WASHER OUTSIDE DIAMETER | 0.588 INCHES MINIMUM AND |
| 0.610 INCHES MAXIMUM |
| PRIMARY WASHER MATERIAL THICKNESS | 0.028 INCHES MINIMUM AND |
| 0.034 INCHES MAXIMUM |