| CHAMFER ANGLE | 30.0 DEGREES MINIMUM AND 45.0 DEGREES MAXIMUM |
| FASTENER LENGTH | 1.413 INCHES MINIMUM AND 1.443 INCHES MAXIMUM |
| HEAD DIAMETER | 0.419 INCHES MINIMUM AND 0.438 INCHES MAXIMUM |
| HEAD HEIGHT | 0.209 INCHES MINIMUM AND 0.219 INCHES MAXIMUM |
| HEAD STYLE | FLAT CHAMFER |
| INTERNAL DRIVE STYLE | HEXAGON |
| MATERIAL DOCUMENT AND CLASSIFICATION | NAS-21472 NATIONAL STD/SPEC SINGLE MATERIAL RESPONSE OVERALL |
| MATERIAL | STEEL CORROSION RESISTING OVERALL |
| NOMINAL THREAD DIAMETER | 0.2500 INCHES |
| SHOULDER DIAMETER | 0.289 INCHES NOMINAL ALL SHOULDERS |
| SHOULDER SHAPE | ROUND ALL SHOULDERS |
| SHOULDER LENGTH | 1.000 INCHES NOMINAL ALL SHOULDERS |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | SCREW,SHOULDER,SOCKET HEAD,HEXAGON ALLOY STEEL OR NICKEL-COPPER ALLOY,UNC-3A |
| SPECIFICATION/STANDARD DATA | 80205-NAS-51975 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| WIDTH ACROSS FLATS | 0.156 INCHES NOMINAL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | ASTM B633,TYPE II,CLASS FE/ZN 5 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | ZINC OVERALL |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.418 INCHES MINIMUM AND 0.438 INCHES MAXIMUM |
| THREAD SERIES DESIGNATOR | UNIFIED NATIONAL COARSE (UNC) |
| THREAD QUANTITY PER INCH | 20 |