What does Steel Rebars hrb400 mean

HRB400 Chinese name is hot rolled ribbed bar, diameter is 6 ~ 100mm. National mandatory standard GB1499.2 -- 2007 "reinforced concrete with hot rolled ribbed bar" from March 1, 2008 began to implement. The standard yield strength of the steel bar HRB400 is 400MPa, and the design value is 360MPa.

1, HRB is hardness value, means hot-Rolled ribbed -steel Bar Hot rolled Ribbed bar, refers to the Rockwell hardness measurement (HR) class B scale, represents the hardness of the steel being measured how many HRB, the number after is the yield strength of the bar.

2, Third grade Rebars (HRB400 above) is also threaded Steel Rebars, similar to the diameter of Second grade Steel Rebars, higher strength, but the price is also high, has been gradually promoted.

3. Secondary steel bar (HRB335) is threaded steel bar, the diameter of 12-25 is the most common, used in beams, columns, shear walls and so on. No matter how large the diameter is, it is rarely used in civil and industrial construction. It is often used in mass concrete, such as hydraulic engineering.

4, The first grade steel bar (HPB300) is generally smooth steel, belonging to the hot rolled round steel bar, commonly known as wire rod, 6-12 rounds of the most common. In architecture, it is often used to make stirrups, distribution bars of plates, stirrups, wall reinforcement and so on.

How to choose reinforcement

1. Check the surface quality, finish and color of the steel bar. The surface of the steel bar should be smooth and neat, uniform color, bright and uniform dark blue gray, there should be no cracks, scars and folding visible defects, the end of the steel bar should be basically circular. The end face of inferior steel bar is often elliptical, the surface color is not uniform, rough and uneven, and even there are scars, cracks, folding and other defects. The iron oxide skin produced by rolling is knocked off or wiped.

2. Check the mark, label and quality certificate of the steel bar. The steel bar should be rolled on the surface of the brand mark, also should be rolled in turn with the manufacturer name (or trademark) and diameter (mm) number. According to the standard provisions of the packaging of steel bars should be hung with signs, signs should indicate the enterprise name, product name, implementation standards, product brand, specifications, lot number, and indicate the production license number and QS logo. According to the standard provisions, the product should also be accompanied by a certificate of quality, its main content includes enterprise name, trademark, product name, implementation standards, product brand, specifications, batch number, weight, product performance inspection data, production license number, QS logo, address and other content, and stamped with the special seal of quality certification.