... pipe(API5D,APISEPC7,API5CT) of 2-3/8",2-7/8",3-1/2,4",4-1/2",5 ... upon producing various oil drilling tools including Drill Pipe, Drill Collar, Heavy Weight Drill Pipe, Kelly,Pup Joint and so ... or plastic steel thread protectors on the connections. Drill pipes of our company are produced in accordance ... &7-1, NS-1. RUSSIA RTN, RUSSIA GOST-R, ISO 9001,ISO 14001, OHSAS 18001, Arnco Hardbanding Certificates ...