Product Description The impregnated diamond casing shoe bit is mainly used in handling casing tubes in shallow earth surfaces, and we have casing shoe bits of different hardness to better fit various casing tube bits. Rod shoes and casing shoes are designed to drill in casings or rods, AW, BW, NW, HW, PW, etc. casing shoes are available. Main Functions * Protect casing ends from distortion * Help casing pass through stratum to bedrock * Carry mud to the earth's surface * Help down-pass of the casing when drill rod is in the hole Size Available of Diamond Casing Shoe Wireline Series: B, N, H, P W Series: RW, EW, AW, BW, NW, HW, PW, SW, UW, ZW, HWT, PWT, BWS, NWS, HT, PT, SZ Metric Series: 46, 56, 66,7 6, 86, 101, 116, 131, 146 X Series: RX, EX, AX, BX, NX, HX, PX, SX, UX, ZX Casing Shoes Sizes ModelOutside Diameter of Casing ShoesInside Diameter of Casing Shoes InchesmmInchesmm AW2. 34559.561.948.26 BW2.96575.312.3760.2 NW3.61591.822.99276 HW4.625117.483.92599.7 HWT4.625117.483.92599.7 PW5.653143.584.855123.3 T2-562.205561.8547 T2-762.992762.63867 T2-863.385862.82371.7 T2-1013.9761013.03177 T6-1013.9761013.44587.5 T6-1315.1571314.646118 Rod Shoes Sizes ModelOutside Diameter of Rod ShoesInside Diameter of Rod Shoes InchesmmInchesmm BQ2. 34559.561.7845.21 NQ2.96575.312.3760.2 HQ3.61591.822.99276 PQ4.75120.663.985101.22Buy Drill Bits and Reaming Shells website:http://www.china-zjtk.com/drill-bits-and-reaming-shells/