Non-Magnetic Drill Collar            Made of chrome manganese low carbon austenitic alloy, has been tested for years of complex drilling situation, with the complete production line that adopt the latest technology including melting, forging, machining and heat treatment , the quality is controlled accurately. All threads are cold worked, and they are machined with CNC Lathes.        Features: 1, The chemical composition be controlled strictly during the refining and forging process. 2,High strength of mechanical properties, lower Magnetic permeability, outstanding resistant to stress corrosion cracking and no tendency to galling   Mechanical Properties OD Size Yield Strength 0.2 Mpa(psi) Tensile Strength b Mpa(psi) Elongation 4% Reduction of are % Impact Ft.1b 3 1/8~6 3/4 758 (110,000) 827 (120,000) 18 50 50 7~10 689 (100,000) 758 (110,000) 20