Difference between EN8 and MS material
EN8 has higher tensile strength than MS material and bit costly.
Difference between EN8 and EN8d material
EN8 is through-hardened medium carbon steel. It used to manufacture parts such as axles, shafts, gears, studs, bolts etc, and can be easily machinable. EN8D has enhanced wear resistance and it’s a carbon steel. It is a surface-hardened version of EN8 by induction processes. It is useful in general engineer and automobile components.