... clays, salts and soft li mestones. Size and IADC available: 3 3/4" to 26" IADC 415,435,445,417,437,517,537 ... ”),215.9mm(8 1/2”),222.2mm8 3/4”) 241.3(9 1/2”),244.4(9 5/8”),250.8(9 7 ... ”)311.1(12 1/4”),346.0 (13 5/8”),349.2(13 3/4”)374.6(14 3/4”)381(15”),393.7 ... high toughness and durability suitable for different rock formation)(1) Quick Details Place of Origin:Hebei China (Mainland)Brand Name: ...