Drill Pipe 1.OD:3 1/2,4",4 1/2",5",5 1/2" 2.Steel grade: E75, ... X95,G105,S135 3.MOQ:25 tons 4.Certificates : API 5DP,API7-1 Main feature: A ... strength and long fatigue life Internal Coating Feature: A.High abrasion resistance and low friction factor B ... resistance E. Good corrosion resistance Hardbanding Feature: A. Good balance between antiwear and friction-reduction B ...