| COUNTERSINK ANGLE | 120.0 DEGREES MAXIMUM OVERALL |
| LOCKING FEATURE | PREVAILING TORQUE ALL METAL DESIGN |
| NUT STYLE | HEXAGON |
| OVERALL HEIGHT | 0.313 INCHES MINIMUM AND 0.328 INCHES MAXIMUM |
| MATERIAL | STEEL OVERALL |
| NOMINAL THREAD SIZE | 0.438 INCHES |
| WASHER OUTSIDE DIAMETER | 0.708 INCHES MAXIMUM |
| WASHER THICKNESS | 0.035 INCHES NOMINAL |
| WIDTH ACROSS FLATS | 0.494 INCHES MINIMUM AND 0.504 INCHES MAXIMUM |
| SPECIFICATION/STANDARD DATA | 80205-NAS1291 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416,CL FED SPEC SINGLE TREATMENT RESPONSE OR 2 FED STD 9TH TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM OVERALL |
| TEMP RATING | 450.0 FAHRENHEIT MAXIMUM |
| THREAD CLASS | 3B |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD QUANTITY PER INCH | 20 |
| THREAD SERIES | UNIFIED NATIONAL JOINT FINE (UNJF) |