1.OD:2 3/8"-6 5/8" 2.Grade:E,X,G,S 3.Upset:IU,EU, ... years, we've been exploring and developing upon producing various oil drilling tools including Drill Pipe, Drill Collar, Heavy Weight Drill ... produced in accordance to Standards of API 5DP, API7 &7-1, NS-1. RUSSIA RTN, RUSSIA GOST-R, ISO 9001,ISO 14001 ... , OHSAS 18001, Arnco Hardbanding Certificates and so on. 2 3/8--5 1/2 drill pipe