This question gets into a difficult area with respect to materials and standards. There is no real ASTM standard for tubing or hollow bar that includes an equivalent grade to 20MV6/20MnV6/1.5217. ASTM A 572 does cover HSLA bars, so one could certify that 20MV6/20MnV6/1.5217 meets the requirements of Grade 65 according to ASTM A 572, but it is not truly equivalent.
ASTM A 519 is the standard specification for seamless tubing, but it does not include a similar grade to 20MV6. There are essentially 4 providers of seamless tubing in North America (Tenaris/TAMSA, Timken, Michigan Seamless Tubing, and Dofasco) and all of them certify according to ASTM A 519. All of them would produce an equivalent to 20MV6 if there is sufficient volume. Timken produces a MicroTec 2W65, which is their tradename for an equivalent to 20MV6. I strongly recommend Timken, and strongly advise against Tenaris/TAMSA. The cold drawing facility is quite old, and incapable of producing a clean surface on stress-relieved products. Their communication and customer service is extremely poor.
