A36 hot rolled steel round bars are an excellent candidate for most processing techniques. A36 hot rolled steel round bars have a rough, blue-grey finish, dull rounded edges and have inexact dimensions throughout length. A36 material is a low carbon steel, often referred to as mild steel which is long lasting and durable. Common applications include shafts, railings, stakes, ornamental projects, and tines. ASTM A36 / A36M-08 is the standard specification for carbon structural steel.