| DISTANCE FROM CENTERLINE TO TOP OF INTERNAL KEY | 1.380 INCHES NOMINAL |
| HARDNESS RATING | 26.0 ROCKWELL C MINIMUM AND 33.0 ROCKWELL C MAXIMUM |
| HOLE DIAMETER | 3.250 INCHES NOMINAL |
| INTERNAL STRAIGHT KEY WIDTH | 0.240 INCHES MINIMUM AND 0.245 INCHES MAXIMUM |
| INTERNAL KEY QUANTITY | 2 |
| OUTSIDE DIAMETER | 4.250 INCHES NOMINAL |
| MATERIAL DOCUMENT AND CLASSIFICATION | MIL-S-18729,COND N MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| MATERIAL THICKNESS | 0.090 INCHES NOMINAL |
| MATERIAL | STEEL COMP 4130 OVERALL |
| MINIMUM TENSILE STRENGTH | 125000 POUNDS PER SQUARE INCH |
| PART NAME ASSIGNED BY CONTROLLING AGENCY | NAVY SPECIAL PROJECT |
| SPECIAL FEATURES | DRILL 4 HOLES 0.265 DIA EQUALLY SPACED ON 3.750 IN. DIA BOLT CIRCLE |
| STYLE DESIGNATOR | KEY |
| SURFACE FINISH | 90.0 MICROINCHES ALL SURFACES |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | MIL-C-13924,CL 1 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | OXIDE FILM OVERALL |