| FASTENER LENGTH | 0.500 INCHES NOMINAL |
| HARDNESS RATING | 40.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM PRIMARY WASHER |
| HEAD DIAMETER | 0.473 INCHES MINIMUM AND 0.492 INCHES MAXIMUM |
| HEAD HEIGHT | 0.130 INCHES MINIMUM AND 0.144 INCHES MAXIMUM |
| HEAD STYLE | PAN NO. 2 |
| INTERNAL DRIVE STYLE | CROSS RECESS TYPE 1 |
| MATERIAL DOCUMENT AND CLASSIFICATION | SAE ASSN STD ALL MATERIAL RESPONSES FASTENER |
| MATERIAL DOCUMENT AND CLASSIFICATION | SAE ASSN STD ALL MATERIAL RESPONSES PRIMARY WASHER |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| PRIMARY WASHER MATERIAL THICKNESS | 0.023 INCHES MINIMUM AND 0.028 INCHES MAXIMUM |
| PRIMARY WASHER OUTSIDE DIAMETER | 0.494 INCHES MINIMUM AND 0.510 INCHES MAXIMUM |
| PRIMARY WASHER STYLE | FLAT EXTERNAL TEETH |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416,TY 1,CL 3 FED SPEC 1ST TREATMENT RESPONSE OR QQ-Z-325,TY 1,CL 3 FED SPEC 2ND TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM OR ZINC OVERALL |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.341 INCHES MINIMUM AND 0.477 INCHES MAXIMUM |
| THREAD QUANTITY PER INCH | 20 |
| THREAD SERIES DESIGNATOR | UNIFIED NATIONAL COARSE (UNC) |
| WASHER QUANTITY | 1 |