| DEPARTURE FROM CITED DESIGNATOR | AS MODIFIED BY PITCH DIA AND FLUTE DATA |
| FLUTE QUANTITY | 2 |
| LENGTH | 0.2500 INCHES MINIMUM AND 0.3124 INCHES MAXIMUM SQUARE END |
| MATERIAL | STEEL OVERALL |
| NONDEFINITIVE SPEC/STD DATA | 2 TYPE AND A SERIES AND B STYLE |
| OVERALL LENGTH | 2.469 INCHES MINIMUM AND 2.531 INCHES MAXIMUM |
| SHANK DIAMETER | 0.2535 INCHES MINIMUM AND 0.2550 INCHES MAXIMUM |
| STARTING CHAMFER TYPE | PLUG |
| STYLE DESIGNATOR | SPIRAL POINTED FLUTE |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD FORMING METHOD | GROUND |
| THREAD LENGTH | 1.000 INCHES NOMINAL |
| THREAD SIZE AND SERIES/TYPE DESIGNATOR | 0.250-20 UNC |
| THREAD PITCH DIAMETERS | +0.2268 TO 0.2273 INCHES |
| THREAD STRUCTURE | REGULAR |
| WIDTH ACROSS FLATS | 0.187 INCHES MINIMUM AND 0.191 INCHES MAXIMUM |