| DIAMETER OF RECESSED PORTION OF SHANK | 0.282 INCHES MINIMUM AND 0.286 INCHES MAXIMUM |
| HARDNESS RATING | 26.0 ROCKWELL C MINIMUM AND 32.0 ROCKWELL C MAXIMUM |
| LENGTH OF RECESSED PORTION OF SHANK | 0.253 INCHES NOMINAL |
| OVERALL LENGTH | 1.550 INCHES MINIMUM AND 1.570 INCHES MAXIMUM |
| MATERIAL | STEEL COMP 4140 |
| NOMINAL THREAD SIZE | 0.312 INCHES NUT THREAD |
| NOMINAL THREAD SIZE | 0.312 INCHES STUD THREAD |
| STYLE DESIGNATOR | RECESSED |
| SURFACE TREATMENT | CADMIUM OVERALL |
| THREAD CLASS | 2A NUT THREAD |
| THREAD CLASS | 2A STUD THREAD |
| THREAD DIRECTION | RIGHT-HAND NUT THREAD |
| THREAD DIRECTION | RIGHT-HAND STUD THREAD |
| THREAD LENGTH | 0.560 INCHES MINIMUM AND 0.645 INCHES MAXIMUM NUT THREAD |
| THREAD LENGTH | 0.650 INCHES MINIMUM AND 0.760 INCHES MAXIMUM STUD THREAD |
| THREAD SERIES DESIGNATOR | UNF NUT THREAD |
| THREAD SERIES DESIGNATOR | UNIFIED NATIONAL COARSE (UNC) STUD THREAD |
| THREAD QUANTITY PER INCH | 18 STUD THREAD |
| THREAD QUANTITY PER INCH | 24 NUT THREAD |