LEMAN stainless steel cutting discs is about 4″ or deeper

LEMAN stainless steel cutting discs Some concrete has steel bars (reinforced concrete). If your cutting depth is about 4″ or deeper, you may meet the steel bars halfway. There are diamond blades specially for cutting reinforced concrete.
The curing time of concrete varies. Fresh (green) concrete is more abrasive, and old (cured) concrete is harder. Diamond blades for cutting green concrete and cured concrete are also designed to be different.