1/2 in Steel Undersized Machine Key with Plain Finish/ OVERALL LENGTH: 0.500 INCHES NOMINAL OVERALL WIDTH: 0.187 INCHES NOMINAL END ITEM IDENTIFICATION: OASIS/OAMCM MISSION KIT SPT TYP 1 HARDNESS RATING: 85.0 ROCKWELL B NOMINAL OVERALL PART NAME ASSIGNED BY CONTROLLING AGENCY: MACHINE KEY SPECIAL FEATURES: UNDERSIZED; SQUARE END TYPE; PLAIN FINISH; TENSILE STRENGTH 64,000 PSI; ROCKWELL HOLDS PULLEYS AND GEARS ON TRANSMISSION SHAFTS MATERIAL: STEEL OVERALL STYLE DESIGNATOR: B15 PLAIN