| COUNTERBORE DIAMETER | 0.260 INCHES MINIMUM AND 0.270 INCHES MAXIMUM NUT |
| DISTANCE FROM CENTERLINE TO FLAT | 0.155 INCHES MINIMUM AND 0.165 INCHES MAXIMUM |
| HARDNESS RATING | 19.0 ROCKWELL C MINIMUM AND 26.0 ROCKWELL C MAXIMUM |
| MATERIAL DOCUMENT AND CLASSIFICATION | AMS 6322 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | NAVY SPECIAL PROJECT |
| MATERIAL | STEEL COMP 8740 OVERALL |
| NOMINAL THREAD SIZE | 0.250 INCHES |
| NUT COUNTERBORE DEPTH | 0.160 INCHES MINIMUM AND 0.180 INCHES MAXIMUM NUT |
| NUT DIAMETER | 0.470 INCHES MINIMUM AND 0.480 INCHES MAXIMUM |
| NUT HEIGHT | 0.620 INCHES MINIMUM AND 0.660 INCHES MAXIMUM |
| NUT STYLE | CLINCH |
| PILOT LENGTH | 0.160 INCHES MINIMUM AND 0.180 INCHES MAXIMUM |
| PILOT DIAMETER | 0.347 INCHES MINIMUM AND 0.349 INCHES MAXIMUM |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | AMS 2400 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM OVERALL |
| THREAD CLASS | 3B |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD QUANTITY PER INCH | 28 |
| THREAD SERIES | UNIFIED NATIONAL JOINT FINE (UNJF) |