420A / 420B / 420C (1.4021 / 1.4028 / 1.4034)
420 grade, also known as X20Cr13, belongs to the group of martensitic stainless steel. Under normal conditions, it has an average corrosion resistance and is not suitable for extremely corrosive environments. This grade materials attract magnets because they do not cantain nickel.
420 grade is classified into three groups as 420A, 420B and 420C according to the carbon ratios in their composition.
The most important property of 420 grade is that it can be hardened by heat treatment. with heat treatment. After the heat treatment, its hardness values can increase 2 - 2.5 times. The machinability of the 420 grade in the annealed state is good in proportion to the amount of carbon it contains. In annealed state, is suitable for machining and its sawdust is brittle.