| FASTENER LENGTH | 1.250 INCHES NOMINAL |
| HARDNESS RATING | 60.0 ROCKWELL B MINIMUM OVERALL |
| HEAD HEIGHT | 0.150 INCHES MINIMUM AND 0.188 INCHES MAXIMUM |
| HEAD STYLE | HEXAGON |
| MATERIAL DOCUMENT AND CLASSIFICATION | FF-B-561,GR B FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| MATERIAL | STEEL CORROSION RESISTING OVERALL |
| MINIMUM TENSILE STRENGTH | 55000 POUNDS PER SQUARE INCH |
| NONDEFINITIVE SPEC/STD DATA | 1 TYPE AND 1 STYLE AND B GRADE |
| NONMACHINE NOMINAL THREAD DIAMETER | 0.250 INCHES |
| NONMACHINE THREAD STYLE | GIMLET POINT (TYPE A, AB OR BA) |
| SHOULDER DIAMETER | 0.237 INCHES MINIMUM AND 0.260 INCHES MAXIMUM FIRST SHOULDER |
| SHOULDER LENGTH | 0.094 INCHES MINIMUM FIRST SHOULDER |
| SHOULDER SHAPE | ROUND FIRST SHOULDER |
| WIDTH BETWEEN FLATS | 0.425 INCHES MINIMUM AND 0.437 INCHES MAXIMUM |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | ASTM A153-60 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | ZINC OVERALL |