AUS-4 is a simple Japanese steel that no longer plays much of a role on the market – with very few exceptions. It is at the performance level of 440A.

Origin: Japan
Carbon (%): 0,4-0,45
Chrome (%): 13-14,5
Manganese (%): 1
Nickel (%): 0,4
Silicon (%): 1
Phosphorus (%): 0,4
Rockwell (HRC): 55-57