1.OD:2 3/8"-6 5/8" 2.Grade:E,X,G, ... To improve the galling-resistance during initial break-in and drilling operation, all threads are also ... 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 drill pipe