Socket Set Screw, Cup, 1/2 in Overall Length, 3/8-16, Alloy Steel, Black Oxide, PK 100/ THREAD CLASS: 3A THREAD DIRECTION: RIGHT-HAND FASTENER LENGTH: 0.500 INCHES NOMINAL HEAD STYLE: C101 HEADLESS (SETSCREW) POINT DIAMETER: 0.194 INCHES MINIMUM AND 0.212 INCHES MAXIMUM POINT STYLE: F12 CUP INTERNAL DRIVE STYLE: D5 HEXAGON NOMINAL THREAD DIAMETER: 0.375 INCHES WIDTH ACROSS FLATS: 0.1875 INCHES NOMINAL THREAD QUANTITY PER INCH: 16 HARDNESS RATING: 45.0 ROCKWELL C MINIMUM OVERALL AND 53.0 ROCKWELL C MAXIMUM MATERIAL: STEEL OVERALL THREAD SERIES DESIGNATOR: UNC