1.OD:2 3/8"-6 5/8" 2.Grade:E,X,G,S 3.Upset:IU,EU,IEU 4.HB:Arnco100XT,150XT,300XT, Botn1000, ... steel thread protectors on the connections. Drill pipes of our company are 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 ...