| DEPARTURE FROM CITED DESIGNATOR | AS MODIFIED BY SURFACE TREATMENT |
| FASTENER LENGTH | 1.440 INCHES MINIMUM AND 1.500 INCHES MAXIMUM |
| HARDNESS RATING | 30.0 ROCKWELL C MINIMUM AND 37.0 ROCKWELL C MAXIMUM OVERALL |
| HEAD HEIGHT | 0.224 INCHES MINIMUM AND 0.245 INCHES MAXIMUM |
| HEAD STYLE | SQUARE |
| INTERNAL DRIVE STYLE | W/O INTERNAL DRIVE |
| MATERIAL DOCUMENT AND CLASSIFICATION | 66 FED STD ALL MATERIAL RESPONSES OVERALL |
| MATERIAL | STEEL COMP 1010 OR STEEL COMP 1011 OR STEEL COMP 1013 OR STEEL COMP 1015 OR STEEL COMP 1016 OR STEEL COMP 1017 OR STEEL COMP 1018 OR STEEL COMP 1019 OR STEEL COMP 1020 OR STEEL COMP 1035 OR STEEL COMP 1037 OR STEEL COMP 1038 OR STEEL COMP 1039 OR STEEL COMP 1040 OR STEEL COMP 1042 OR STEEL COMP 1043 OR STEEL COMP 1044 OR STEEL COMP 1045 OR STEEL COMP 1212 OR STEEL COMP 1213 OR STEEL COMP 1137 OR STEEL COMP 1139 OR STEEL COMP 1140 OR STEEL COMP 1141 OR STEEL COMP 1144 OVERALL |
| NOMINAL THREAD DIAMETER | 0.312 INCHES |
| NONDEFINITIVE SPEC/STD DATA | 1 TYPE AND 4 STYLE |
| POINT STYLE | CUP |
| WIDTH BETWEEN FLATS | 0.302 INCHES MINIMUM AND 0.312 INCHES MAXIMUM |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | ASTM B633 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | ZINC OVERALL |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 1.330 INCHES MINIMUM AND 1.500 INCHES MAXIMUM |
| THREAD QUANTITY PER INCH | 18 |
| THREAD SERIES DESIGNATOR | UNC |