Electric arc furnace
Small-sized EAF, nominal capacity is less than 30t.
  Medium-sized EAF, nominal capacity is 30~70t.
  Large-sized EAF, nominal capacity is more than 90t.

Billet/bloom caster design
Large-sized slab caster and alloy steel caster

Induction furnace
Working frequency (50 or 60Hz)
Medium frequency (150~10000Hz)
High frequency (10000Hz above)