| CONCENTRIC HOLE DEPTH | 2.656 INCHES NOMINAL |
| CONCENTRIC HOLE DIAMETER | 0.213 INCHES NOMINAL |
| DISTANCE FROM HEAD LARGEST BEARING SURFACE TO SHANK HOLE CENTER | 4.990 INCHES MINIMUM AND 5.010 INCHES MAXIMUM FIRST HOLE |
| FASTENER LENGTH | 5.240 INCHES MINIMUM AND 5.260 INCHES MAXIMUM |
| HARDNESS RATING | 28.0 ROCKWELL C MINIMUM AND 34.0 ROCKWELL C MAXIMUM OVERALL |
| HEAD HEIGHT | 0.406 INCHES NOMINAL |
| HEAD STYLE | HEXAGON |
| INTERNAL THREAD CLASS | 2B COUNTERBORE |
| INTERNAL THREAD DIRECTION | RIGHT-HAND COUNTERBORE |
| INTERNAL THREAD LENGTH | 0.406 INCHES NOMINAL COUNTERBORE |
| MATERIAL | STEEL COMP 5140H OVERALL |
| NOMINAL THREAD DIAMETER | 0.500 INCHES |
| NOMINAL THREAD SIZE | 0.250 INCHES COUNTERBORE |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | NAVY SPECIAL PROJECT |
| SHANK UNTHREADED HOLE DIAMETER | 0.141 INCHES NOMINAL FIRST HOLE |
| SHOULDER DIAMETER | 0.512 INCHES MINIMUM AND 0.519 INCHES MAXIMUM |
| SHOULDER LENGTH | 0.265 INCHES NOMINAL |
| STYLE DESIGNATOR | COUNTERBORE THREADED |
| SPECIAL FEATURES | STRAIGHT KNURL ON SHOULDER |
| WIDTH BETWEEN FLATS | 0.736 INCHES MINIMUM AND 0.750 INCHES MAXIMUM |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD CLASS | 2A |
| THREAD LENGTH | 0.875 INCHES MINIMUM |
| THREAD SERIES DESIGNATOR | UNF |
| THREAD SERIES | UNF COUNTERBORE |
| THREAD QUANTITY PER INCH | 20 |
| THREADS PER INCH | 28 COUNTERBORE |