| THREAD SERIES DESIGNATOR | UNF |
| NOMINAL THREAD DIAMETER | 0.438 INCHES |
| THREAD QUANTITY PER INCH | 20 |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.390 INCHES MINIMUM AND |
| 0.454 INCHES MAXIMUM |
| FASTENER LENGTH | 1.281 INCHES MINIMUM AND |
| 1.313 INCHES MAXIMUM |
| MATERIAL | STEEL COMP 8740 OR |
| STEEL COMP 8630 OR |
| STEEL COMP 8735 OR |
| STEEL COMP 4037 OR |
| STEEL COMP 4140 OR |
| STEEL COMP 4130 OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | MIL-S-6049 MIL SPEC 1ST MATERIAL RESPONSE OR |
| MIL-S-6050 MIL SPEC 2ND MATERIAL RESPONSE OR |
| MIL-S-6098 MIL SPEC 3RD MATERIAL RESPONSE OR |
| AMS 6300 ASSN STD 4TH MATERIAL RESPONSE OR |
| MIL-S-5626 MIL SPEC 5TH MATERIAL RESPONSE OR |
| MIL-S-6758 MIL SPEC 6TH MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM AND |
| CHROMATE OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416 TY 2 CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| HARDNESS RATING | 26.0 ROCKWELL C MINIMUM AND |
| 32.0 ROCKWELL C MAXIMUM OVERALL |
| MINIMUM TENSILE STRENGTH | 125000 POUNDS PER SQUARE INCH |
| SINGLE SHEAR STRENGTH | 11250 POUNDS PER SQUARE INCH |
| HEAD STYLE | BUTTON |
| HEAD DIAMETER | 0.796 INCHES MINIMUM AND |
| 0.828 INCHES MAXIMUM |
| HEAD HEIGHT | 0.203 INCHES MINIMUM AND |
| 0.235 INCHES MAXIMUM |
| INTERNAL DRIVE STYLE | SLOT |
| GROOVE DIAMETER | 0.062 INCHES NOMINAL |
| DISTANCE FROM HEAD LARGEST BEARING SURFACE TO SHANK HOLE CENTER | 1.078 INCHES MINIMUM AND |
| 1.110 INCHES MINIMUM FIRST HOLE |
| SHANK UNTHREADED HOLE DIAMETER | 0.106 INCHES MINIMUM AND |
| 0.116 INCHES MAXIMUM FIRST HOLE |
| SPEC/STD CONTROLLING DATA | |
| MANUFACTURERS CODE | 88044 |
| DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | AN27-20 |
| MANUFACTURERS CODE | 81349 |
| NON-DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | B6812 |