... carbide3)Medium hard with high compressive strength and hard stringers,such as hard sandy mudstone , and sandstone ,etc.List of Size BitsHejian ... baoxing Petroleum Machinery Co., Ltd.ProductSizeIADC CODE TCI Tricone Bit3 7/8 ,5 ... 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/8,12 1/413 3/4, 17 1/2,22, 24 ... /2, 6 1/27 7/8,8 1/2,8 3/410 5/8,12 1/413 3/4, 17 1/2,22, 24 ...