Frequently asked questions.

Frequently asked questions.

How to distinguish between cold rolled steel bars and hot rolled steel bars?

The difference between hot rolled steel bar and cold rolled steel bar: the difference between them is not only the difference between hot and cold but also the strength, yield point, tensile strength and so on. Let’s have a look.

Hot rolled steel bar is a kind of finished steel bar formed by hot rolling and natural cooling. It is made of low carbon steel and ordinary alloy steel under high temperatures. It is mainly used for the reinforcement of reinforced concrete and prestressed concrete structures. It is one of the most widely used steel products in civil engineering. Generally, the steel bars with a diameter of 6.5-9 mm are mostly rolled into coils; The diameter of 10-40mm is usually 6-12M long. Hot rolled steel bars are directly processed on the steel mold in the steel furnace in the steel processing plant, that is, the hot (so-called “hot rolling”) products come out of the furnace and can be used after cooling.

Cold rolled ribbed steel bar

Cold rolled steel bars are produced by cold mill rolls processing of hot rolled steel bars, such as cold drawing and drawing of steel bars at room temperature. The yield strength of the hot-rolled steel bar is low and its plasticity is good. Cold rolled steel bars have higher yield strength and poor plasticity, and their ultimate tensile and compressive strength are the same.
How can we tell which is hot rolled and which is cold rolled at a glance? The initials of hot rolled steel bars are "H", such as HRB335 and hrb40 with hot rolled ribs, and the initials of cold-rolled steel bars are "C", such as crb550 and crb650 with cold-rolled ribs. It is easy to distinguish the beginning letters of hot-rolled and cold-rolled steel bars by remembering them.