... ",4-1/2",5",5-1/2"oil drilling pipe :-Drilling pipe,heavy weight drilling pipe,tubing pipe,casing pipe. We can produced ... upon producing various oil drilling tools including Drill Pipe, Drill Collar, Heavy Weight Drill Pipe, Kelly,Pup Joint and so on. Our ... . To improve the galling-resistance during initial break-in and drilling operation, all threads are also phosphated or coppered, and all ...