| THREAD SERIES DESIGNATOR | UNC |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 20 |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 1.590 INCHES MINIMUM AND |
| 1.750 INCHES MAXIMUM |
| FASTENER LENGTH | 1.690 INCHES MINIMUM AND |
| 1.750 INCHES MAXIMUM |
| MATERIAL | STEEL OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | SAE J489 GR 2 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | AMS 2400 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| HARDNESS RATING | 40.0 ROCKWELL C MINIMUM AND |
| 50.0 ROCKWELL C MAXIMUM OVERALL |
| HEAD STYLE | HEXAGON |
| HEAD HEIGHT | 0.172 INCHES MINIMUM AND |
| 0.190 INCHES MAXIMUM |
| WIDTH BETWEEN FLATS | 0.367 INCHES MINIMUM AND |
| 0.375 INCHES MAXIMUM |
| INTERNAL DRIVE STYLE | SLOT |
| WASHER QUANTITY | 1 |
| PRIMARY WASHER STYLE | FLAT EXTERNAL TEETH |
| PRIMARY WASHER OUTSIDE DIAMETER | 0.494 INCHES MINIMUM AND |
| 0.510 INCHES MAXIMUM |
| PRIMARY WASHER MATERIAL THICKNESS | 0.023 INCHES MINIMUM AND |
| 0.028 INCHES MAXIMUM |
| NONDEFINITIVE SPEC/STD DATA | A TYPE AND |
| 2 GRADE |