N-A-XTRA M550 is a quenched and tempered structural steel produced as heavy plates. N-A-XTRA steel can be supplied in six different grades with a minimum yield strength of 550, 620, and 700 MPa (79.8, 89.9, and 101.5 ksi). Some grades are delivered with different toughness properties. This last quality is for low service temperature with minimum impact energy at -40 deg C (-40 deg F) for grade N-A-XTRA M in a thickness range from 3 to 120 mm (0.118-4.724 in.). This datasheet provides information on composition and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-744. Producer or source: ThyssenKrupp Steel Europe AG.