| FASTENER LENGTH | 0.620 INCHES MINIMUM AND 0.630 INCHES MAXIMUM |
| HARDNESS RATING | 45.0 ROCKWELL C MINIMUM AND 53.0 ROCKWELL C MAXIMUM OVERALL |
| HEAD STYLE | HEADLESS (SETSCREW) |
| INTERNAL DRIVE STYLE | HEXAGON |
| MATERIAL DOCUMENT AND CLASSIFICATION | 66 FED STD SINGLE MATERIAL RESPONSE OVERALL |
| MATERIAL | STEEL OVERALL |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | NAVY SPECIAL PROJECT |
| POINT STYLE | FLAT |
| SPECIAL FEATURES | ONEDRILLEDHOLE0.047INDIADRILLEDTHROUGHSOCKETRECESS |
| WIDTH ACROSS FLATS | 0.125 INCHES MINIMUM AND 0.127 INCHES MAXIMUM |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416 TYPE 2 CLASS 3 FED SPEC ALL TREATMENT RESPONSES OVERALL |
| SURFACE TREATMENT | CADMIUM AND CHROMATE OVERALL |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.625 INCHES MAXIMUM |
| THREAD QUANTITY PER INCH | 28 |
| THREAD SERIES DESIGNATOR | UNF |