In construction, there are many types of steel commonly used, among which round bars and rebar are the most prevalent. The main differences between them are as follows. Today, we’ll briefly discuss these differences.
Round Bars (HPB Series)
The surface of round bars is relatively smooth. If embedded in concrete, they can be pulled out with just a slight tug.
Rebar (HRB Series)
The outer surface of rebar features spiral-shaped ribs. Some resemble crescent moons, while others resemble spirals.
The purpose of these ribs is to grip the concrete tightly, ensuring they never let go even when subjected to stress and deformation.
Round Bar (HPB300)
Round bar belongs to the carbon steel category, with the steel grade designated as Q235. It has average strength, with a yield strength of around 300 MPa. Advantages: high toughness and easy to bend.
Rebar (HRB400E)
Rebar belongs to the low-alloy steel category. HRB335-grade rebar is 20MnSi (20 manganese-silicon). HRB400-grade rebar is 20MnSiV, 20MnSiNb, 20MnTi, and so on. Note the “E”—it stands for earthquake resistance.
It not only withstands compression but also offers first-rate tensile strength.
Many customers ask, “Is rebar heavier than round bar of the same diameter?”
Theoretically: They weigh the same!
In the theoretical calculation formula of the national standard, to facilitate trading and accounting, regardless of the number of ribs on the surface, the theoretical weight per meter for ribbed rebar and round bar of the same diameter is calculated using a unified formula.
Of course, in reality, ribbed rebar is slightly heavier due to the additional ribs (this is called a “negative deviation”), but when calculating material costs, everyone uses the same “system of measurement.”
Post time: Jun-30-2026
