| THREAD SERIES DESIGNATOR | UNC |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 20 |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.750 INCHES MAXIMUM |
| FASTENER LENGTH | 0.719 INCHES MINIMUM AND |
| 0.750 INCHES MAXIMUM |
| 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 OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | SAE ASSN STD ALL MATERIAL RESPONSES OVERALL |
| SURFACE TREATMENT | CADMIUM OR |
| ZINC OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416,TY 1,CL 3 FED SPEC 1ST TREATMENT RESPONSE OR |
| QQ-Z-325,TY 1,CL 3 FED SPEC 2ND TREATMENT RESPONSE OVERALL |
| HARDNESS RATING | 38.0 ROCKWELL C MINIMUM AND |
| 43.0 ROCKWELL C MAXIMUM OVERALL |
| HEAD STYLE | SQUARE |
| HEAD HEIGHT | 0.178 INCHES MINIMUM AND |
| 0.196 INCHES MAXIMUM |
| WIDTH BETWEEN FLATS | 0.241 INCHES MINIMUM AND |
| 0.250 INCHES MAXIMUM |
| INTERNAL DRIVE STYLE | W/O INTERNAL DRIVE |
| POINT STYLE | CONE |
| SPEC/STD CONTROLLING DATA | |
| MANUFACTURERS CODE | 21450 |
| DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | 185671 |