| COUNTERBORE DIAMETER | 0.283 INCHES MINIMUM AND 0.288 INCHES MAXIMUM NUT |
| HARDNESS RATING | 39.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM |
| LOCKING FEATURE | PREVAILING TORQUE ALL METAL DESIGN |
| NUT COUNTERBORE DEPTH | 0.087 INCHES MINIMUM AND 0.097 INCHES MAXIMUM NUT |
| NUT STYLE | FLAT WITH TURNED UP EDGE |
| OVERALL HEIGHT | 0.280 INCHES MAXIMUM |
| MATERIAL DOCUMENT AND CLASSIFICATION | MIL-S-5000 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5626 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE NUT |
| MATERIAL | STEEL COMP E4340 OR STEEL COMP 4140 OR STEEL COMP 8740 NUT |
| MATERIAL | STEEL WASHER |
| NOMINAL THREAD SIZE | 0.250 INCHES |
| SPECIAL FEATURES | WASHER ROCKWELL C SCALE 40.0 MIN AND 45.0 MAX |
| THREAD SERIES | UNIFIED NATIONAL JOINT FINE (UNJF) |
| THREAD QUANTITY PER INCH | 28 |
| WASHER OUTSIDE DIAMETER | 0.460 INCHES MAXIMUM |
| WIDTH ACROSS FLATS | 0.306 INCHES MINIMUM AND 0.313 INCHES MAXIMUM |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416,TY 2,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM AND CHROMATE OVERALL |
| TEMP RATING | 450.0 FAHRENHEIT MAXIMUM |
| THREAD CLASS | 3B |
| THREAD DIRECTION | RIGHT-HAND |