| CONCENTRIC HOLE DIAMETER | 0.174 INCHES MINIMUM AND 0.180 INCHES MAXIMUM |
| FASTENER LENGTH | 0.495 INCHES MINIMUM AND 0.505 INCHES MAXIMUM |
| HEAD HEIGHT | 0.370 INCHES MINIMUM AND 0.380 INCHES MAXIMUM |
| HEAD STYLE | HEXAGON |
| INTERNAL THREAD CLASS | 2B COUNTERBORE |
| INTERNAL THREAD DIRECTION | RIGHT-HAND COUNTERBORE |
| INTERNAL THREAD LENGTH | 0.250 INCHES MINIMUM COUNTERBORE |
| MATERIAL DOCUMENT AND CLASSIFICATION | ASTM A108 ASSN STD ALL MATERIAL RESPONSES OVERALL |
| MATERIAL | STEEL COMP 1018 OR STEEL COMP 1019 OR STEEL COMP 1020 OR STEEL COMP 1022 OR STEEL COMP 1025 OR STEEL COMP 1212 OR STEEL COMP 1213 OVERALL |
| NOMINAL THREAD DIAMETER | 0.438 INCHES |
| NOMINAL THREAD SIZE | 0.438 INCHES COUNTERBORE |
| SPECIAL FEATURES | PAC SFTT IS FOR STL MATL ONLY |
| STYLE DESIGNATOR | COUNTERBORE THREADED |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | MIL-C-14550 CL 2 MIL SPEC 1ST TREATMENT RESPONSE OR MIL-T-10727 TY 1 MIL SPEC 2ND TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | COPPER OR TIN OVERALL |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.395 INCHES MINIMUM AND 0.505 INCHES MAXIMUM |
| THREAD SERIES DESIGNATOR | UNF |
| THREAD SERIES | UNS COUNTERBORE |
| THREAD QUANTITY PER INCH | 20 |
| THREADS PER INCH | 24 COUNTERBORE |
| WIDTH BETWEEN FLATS | 0.615 INCHES MINIMUM AND 0.625 INCHES MAXIMUM |