Product Description: 215.9mm IADC137 Industrial standard:SY/T5164 Payment terms: T/T,Western Union,and L/C are acceptable Applications:Medium hard with high compressive strength and high abrasiveness, such as limestone, dolomite, sandstone and chert, etc. Note:other size and IADC is available For more info: www.crossingbit.com Hebei Crossing Drill Bit Manufacture CO.,LTD