| THREAD SERIES DESIGNATOR | UNF |
| NOMINAL THREAD DIAMETER | 0.312 INCHES |
| THREAD QUANTITY PER INCH | 24 |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.372 INCHES MINIMUM AND |
| 0.408 INCHES MAXIMUM |
| FASTENER LENGTH | 1.387 INCHES MINIMUM AND |
| 1.403 INCHES MAXIMUM |
| MATERIAL | STEEL COMP 440F OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | ASTM A582 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT | PASSIVATE OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| HARDNESS RATING | 55.0 ROCKWELL C MINIMUM OVERALL |
| HEAD STYLE | HEXAGON |
| HEAD HEIGHT | 0.223 INCHES MINIMUM AND |
| 0.243 INCHES MAXIMUM |
| WIDTH BETWEEN FLATS | 0.555 INCHES MINIMUM AND |
| 0.562 INCHES MAXIMUM |
| EXTERNALLY RELIEVED BODY DIAMETER QUANTITY | 3 |
| FIRST DIAMETER FROM HEAD | 0.160 INCHES MINIMUM AND |
| 0.180 INCHES MAXIMUM |
| SECOND DIAMETER FROM HEAD | 0.760 INCHES MINIMUM AND |
| 0.780 INCHES MAXIMUM |
| THIRD DIAMETER FROM HEAD | 0.995 INCHES MINIMUM AND |
| 1.015 INCHES MAXIMUM |
| DISTANCE FROM LARGEST BEARING SURFACE OF HEAD TO END OF FIRST DIAMETER | 0.261 INCHES MINIMUM AND |
| 0.265 INCHES MAXIMUM |
| DISTANCE FROM LARGEST BEARING SURFACE OF HEAD TO END OF THIRD DIAMETER | 0.303 INCHES MINIMUM AND |
| 0.312 INCHES MAXIMUM |
| SPECIAL FEATURES | PAINT ONE COAT OF PRIMER TO MIL-P-23377 OR MMS 425 AND ONE COAT OF LUSTERLESS MATT BLACK NO. 3708 FED STD 595 TO TTE 527 ON HEAD OF SCREW ONLY |
| THE MANUFACTURERS DATA | |
| MANUFACTURERS CODE | 55972 |
| DESIGN CONTROL REFERENCE | 2797921-2 |