1.OD:2 3/8"-6 5/8" 2.Grade:E,X,G,S 3.Upset:IU,EU,IEU 4.HB:Arnco100XT,150XT,300XT, ... . All threads are machined by CNC Lathes and inspected with API Spec standard thread gauges. To improve the galling- ... roots are cold rolled. The products shall be equipped with pressed steel or plastic steel thread protectors on the ... , OHSAS 18001, Arnco Hardbanding Certificates and so on. 2 3/8--5 1/2 drill pipe