| FASTENER LENGTH | 0.844 INCHES MINIMUM AND 0.875 INCHES MAXIMUM |
| HARDNESS RATING | 40.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM PRIMARY WASHER |
| HEAD HEIGHT | 0.270 INCHES MINIMUM AND 0.295 INCHES MAXIMUM |
| HEAD STYLE | HEXAGON |
| MATERIAL DOCUMENT AND CLASSIFICATION | SAE ASSN STD ALL MATERIAL RESPONSES PRIMARY WASHER |
| MATERIAL | STEEL COMP 1050 OR STEEL COMP 1566 OVERALL |
| NOMINAL THREAD DIAMETER | 0.375 INCHES |
| PRIMARY WASHER MATERIAL THICKNESS | 0.035 INCHES NOMINAL |
| PRIMARY WASHER OUTSIDE DIAMETER | 0.640 INCHES MINIMUM AND 0.654 INCHES MAXIMUM |
| PRIMARY WASHER STYLE | FLAT EXTERNAL TEETH |
| WASHER QUANTITY | 1 |
| WIDTH BETWEEN FLATS | 0.551 INCHES MINIMUM AND 0.562 INCHES MAXIMUM |
| SURFACE TREATMENT | CADMIUM OR ZINC FASTENER |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD CLASS | 2A |
| THREAD LENGTH | 0.761 INCHES MINIMUM AND 0.875 INCHES MAXIMUM |
| THREAD SERIES DESIGNATOR | UNF |
| THREAD QUANTITY PER INCH | 24 |