Attributes . Low-Carbon Steel (carbon alloy less than 0.25%) / Medium carbon steel (carbon content 0.25 to 0.45%) / High Carbon Steel (C with a content over 0.45%) / Alloy Steel (SCM) / Stainless steel (SUS) / Quenched and tempered steel (25 to 35 HRC) / Quenched and tempered steel (35 to 45 HRC) / Ductile Cast Iron (FCD) / Copper (Cu) / Aluminum Rolled Material (AL) / Aluminum Alloy Casting (AC, ADC) . Names