... compressive strength, very soft formations.2)TCI bits maximize the use of both conical and chisel tungsten carbide inserts of large diameters ... 535 Medium Formation TCI Tricone Bits1)The 535 features aggressive chisel tungsten carbide inserts on the heel rows and inner rows ... Main Type Available Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8",12 ... 8",4 3/4",6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8", ...