The mill casing pipe made by our company is made of high strength alloy steel pipe.The mill casing pipe can be divided into two types:Collar casing and Flush casing .The Flush casing can be divided into

single buckle and double buckle.

The minimum clearance between borehole and mill casing pipe is 12.7mm.The minimum clearance between mill casing pipe and the fish is 3.2mm.In weak formation ,the length of mill casing pipe can be extended appropriately,and in hard

formationonly use one mill casing pipe at a time.