| NONMACHINE THREAD STYLE | GIMLET POINT (TYPE A, AB OR BA) |
| NONMACHINE NOMINAL THREAD DIAMETER | 0.250 INCHES |
| FASTENER LENGTH | 1.000 INCHES NOMINAL |
| MATERIAL | COPPER ALLOY 651 OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | QQ-C 591 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| HEAD STYLE | HEXAGON |
| HEAD HEIGHT | 0.150 INCHES MINIMUM AND |
| 0.188 INCHES MAXIMUM |
| WIDTH BETWEEN FLATS | 0.425 INCHES MINIMUM AND |
| 0.438 INCHES MAXIMUM |
| SHOULDER SHAPE | ROUND FIRST SHOULDER |
| SHOULDER DIAMETER | 0.237 INCHES MINIMUM AND |
| 0.260 INCHES MAXIMUM FIRST SHOULDER |
| SHOULDER LENGTH | 0.094 INCHES MINIMUM FIRST SHOULDER |
| NONDEFINITIVE SPEC/STD DATA | 1 TYPE AND |
| 1 STYLE AND |
| D GRADE |
| SPEC/STD CONTROLLING DATA | |
| MANUFACTURERS CODE | 81348 |
| NON-DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | FF-B-561 STD P/N-634 |
| MANUFACTURERS CODE | 96906 |
| DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | MS16992-634 |