Non-magnetic pressure-bearing weighted drill pipes are made of self-developed LC austenitic non-magnetic steel of grades W1813N, W1813NHS, W2014N, ZYNM7 ,ZYNM9 and ZYNM9HS. They comply with API SPEC 7-1/7-2 /DS-1 and standards of this Company. The roots of threads and bore surfaces can be cold-rolled. And double-shoulder threads and special threads of other specifications can be processed. This Company is able to produce various non-standard products.