Songshun Steel — Steel Round Bar

Steel bar which is the solid long steel with round shape section. It was widely used in the industry due to the good plasticity. But the application on constructional engineering is quite less. Instead, the deformed steel bar is more popular in construction engineering.

There are several types of the steel bar. Including alloy steel bar, mould steel bar, carbon steel bar, high speed steel bar, mild steel bar, spring steel bar, tool steel bar and etc. But the 4140 steel bar, 1045 steel bar, 4130 steel bar, 4340 steel bar are the common grades for the industry.

Steel Bar Classification

According to the ways of production, they can be split into three types. Including hot rolled steel bar, forged steel bar, cold drawn steel bar.

Hot Rolled Steel Bar

Hot roll is the most useful way of production. People use it to produce steel sheets, steel tubes and etc. The common size for hot rolled steel is 5.5mm – 250mm of Dia. If the dia is on the range of 5.5mm – 25mm, the steel usually be used for constructional engineering and all kinds of machine fittings. But if the Dia is bigger than 25mm, that means they were used to make machine parts and raw material for steel tube.

Forged Steel Bar

For most of time, at the condition of the same deformation ratio, the quality of the forged steel is better than the steel that was produced by the free forge rolling. So the key parts of the crane must use the forged steel products.

Cold Drawn Steel Bar

The surface of cold drawn steel round bar is very smooth. And the precision of size is very high, so it can be used directly without any processing. And it has good mechanical properties.

How to Calculate the Weight of Steel Bar

Weight of Steel Bar(kg/m) = Dia(mm)*Dia(mm)*0.00617

Application of Steel Bar


Common carbon steel bar can be used for the project with a lower requirement for tensile strength. Such as the general building works, common standard component and more. Mild steel bar will get better mechanical properties after hardening and tempering. Its good material for shaft, fasteners and etc.

And other alloy steel bars also play a big role in the industry. Such as the 20CrMnTi is important carburizing steel, which is a great material for wheel gear and more. And 35CrMo, 42CrMo are high strength steel. They usually are used for important fittings. Including connecting rod screw of the engine, the screw of cylinder end, the screw of the tire of the heavy load truck and more.

The Difference Between the Steel Bar and Other Rebar

  1. The shape of them is different. Steel bar is smooth without anything, but the surface of rebar is D deformed ribbed bar, R round / plain bar, and I- deformed indented bar. This shape can increase the coagulability between the rebar and concrete.
  2. The chemical composition of them is different. The steel bar usually belongs to common low carbon steel, but most of rebar are alloy steel.
  3. And their strength is also not the same. The strength of steel bar is low, but the rebar strength is higher. For the same size, the tensile strength of steel bar is lower than rebar, but the plasticity is better than rebar.

Common Grades for Steel Bar

Most of steel bar is carbon steel and low alloy steel. Including Q195, Q235, 10#, 20#, 35#, 45#, Q215, 304, 316, 20Cr, 40Cr, 20CrMo, 35CrMo, 42CrMo, 40CrNiMo, GCr15, 65Mn, 50Mn, 50Cr, 3Cr2W8V, 20CrMnTi, 5CrMnMo and etc.