| THREAD SERIES DESIGNATOR | UNF |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 28 |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.562 INCHES MINIMUM |
| FASTENER LENGTH | 0.625 INCHES NOMINAL |
| MATERIAL | STEEL COMP 4140 OR |
| STEEL COMP E4340 OR |
| STEEL COMP 6150 OR |
| STEEL COMP 8735 OR |
| STEEL COMP 8740 OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | MIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR |
| MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR |
| MIL-S-8503 MIL SPEC 3RD MATERIAL RESPONSE OR |
| MIL-S-6098 MIL SPEC 4TH MATERIAL RESPONSE OR |
| MIL-S-6049 MIL SPEC 5TH MATERIAL RESPONSE OVERALL |
| HARDNESS RATING | 36.0 ROCKWELL C MINIMUM AND |
| 43.0 ROCKWELL C MAXIMUM OVERALL |
| MINIMUM YIELD STRENGTH | 130000 POUNDS PER SQUARE INCH |
| HEAD STYLE | FLAT CHAMFER |
| HEAD DIAMETER | 0.375 INCHES MAXIMUM |
| HEAD HEIGHT | 0.250 INCHES MAXIMUM |
| INTERNAL DRIVE STYLE | HEXAGON |
| WIDTH ACROSS FLATS | 0.187 INCHES NOMINAL |
| SURFACE FINISH | 125.0 MICROINCHES OVERALL |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | NAVY SPECIAL PROJECT |