... 3/8", 2 7/8", 3 1/2", 4" ,4 1/2", 5", 5 1/2" ,6 5/82.Steel grade ... : E75,X95,G105,S135 3.Certificates : API 5DP,NS-1 4. Length: R1: 5.3-7.9m R2: ... per customer demand. In line with NS-1requirement. Proprietary product——Tool Joint 1.DPDS——Double Shoulder Tool Joint Developed ... Quality DP-Master's Advantages Strategic partnership with Tuboscope 1)Quality Control-Tuboscope Inspection on all New Drill ...