| LOCKING FEATURE | PREVAILING TORQUE ALL METAL DESIGN |
| OVERALL HEIGHT | 0.281 INCHES MINIMUM AND 0.304 INCHES MAXIMUM |
| MATERIAL | STEEL COMP 1010 OVERALL |
| NOMINAL THREAD SIZE | 0.312 INCHES |
| SPECIAL FEATURES | 24 FLANGE SERRATIONS EQUALLY SPACED/SERR.HEIGHT 0.009/SERR.LENGTH 0.051 |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | SERRATED FLANGED HEX LOCK NUTS |
| WASHER OUTSIDE DIAMETER | 0.686 INCHES MINIMUM AND 0.706 INCHES MAXIMUM |
| WASHER THICKNESS | 0.025 INCHES MINIMUM AND 0.038 INCHES MAXIMUM |
| WIDTH ACROSS FLATS | 0.489 INCHES MINIMUM AND 0.500 INCHES MAXIMUM |
| SURFACE TREATMENT | ZINC OVERALL |
| THREAD CLASS | 2B |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD SERIES | UNIFIED NATIONAL COARSE (UNC) |
| THREAD QUANTITY PER INCH | 18 |