BORE LENGTH: 1.812 IN. NOMINAL; FORK WIDTH: 3.135 IN. MIN AND 3.137 IN. MAX; MATERIAL HARDNESS RATING: 37.9 MIN AND 43.1 MAX ROCKWELL C; SECURING HOLE SIZE: 0.375-24UNF THREADED; DISTANCE FROM MOUNTING FACILITY CENTERLINE TO ARCH CENTERLINE: 1.438 IN. NOMINAL; ARCH INSIDE RADIUS: 2.688 IN. NOMINAL