| FASTENER LENGTH | 0.500 INCHES NOMINAL |
| HARDNESS RATING | 40.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM OVERALL |
| HEAD HEIGHT | 0.172 INCHES MINIMUM AND 0.190 INCHES MAXIMUM |
| HEAD STYLE | HEXAGON |
| MATERIAL DOCUMENT AND CLASSIFICATION | QQ-S-630 FED SPEC 1ST MATERIAL RESPONSE OR FED STD 66 FED STD 2ND MATERIAL RESPONSE OR FED STD 66 FED STD 3RD MATERIAL RESPONSE OVERALL |
| MATERIAL | STEEL COMP 1010 OR STEEL COMP 1050 OR STEEL COMP 1060 OVERALL |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| PRIMARY WASHER MATERIAL THICKNESS | 0.025 INCHES NOMINAL |
| PRIMARY WASHER OUTSIDE DIAMETER | 0.466 INCHES MINIMUM AND 0.478 INCHES MAXIMUM |
| PRIMARY WASHER STYLE | FLAT INTERNAL TEETH |
| WASHER QUANTITY | 1 |
| WIDTH BETWEEN FLATS | 0.428 INCHES MINIMUM AND 0.437 INCHES MAXIMUM |
| SURFACE TREATMENT | CADMIUM OR ZINC OVERALL |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.500 INCHES MINIMUM |
| THREAD SERIES DESIGNATOR | UNC |
| THREAD QUANTITY PER INCH | 20 |