The cold-rolled sheet has higher hardness, finer grain size, and tighter internal structure. Its hardness is generally around HB180. The hot-rolled steel coil is used as raw material, and after pickling to remove the oxide scale, it is cold-rolled. The finished hardened coil is hardened by cold work caused by continuous cold deformation, resulting in an increase in its strength and hardness. This hardening not only increases the hardness of the cold-rolled sheet but may also reduce the toughness and plasticity index and deteriorate the stamping performance. Therefore, it can only be used for parts with simple deformation.

The hot-rolled sheet has lower hardness and better ductility. Its hardness is between HB120-150. The hot-rolled sheet uses a continuous casting slab or initial rolling slab as raw material. After being heated in a step-type heating furnace, it is made through rough rolling and finishing rolling processes. Its surface quality, appearance, and dimensional accuracy are worse than those of cold-rolled sheets, but it has good plasticity and is generally a medium and thick plate.

Hot-rolled ribbed steel bars are divided into three grades: Grade 2 HRB335, Grade 3 HRB400, and Grade 4 HRB500.
In 2018, the state promulgated a new standard for hot-rolled ribbed steel bars for reinforced concrete (GB1499.2-2018). The new standard has three grades of hot-rolled ribbed steel bars, namely HBR335, HBR400, and HBR500.

The difference between different grades of rebar is:
1. Different steel types (different chemical composition): HRB335 grade steel bar is 20MnSi (20 manganese silicon); HRB400 grade steel bar is 20MnSiV or 20MnSiNb or 20MnTi, etc.; while the chemical composition of HBR500 steel bar maintains the upper limit requirements of C, Si, and Mn elements in the original HRB series steel bars, appropriately reduces the upper limit of harmful elements S and P, and uses trace elements V, Nb, Ti,

2. Different strength: The higher the grade of steel bar, the stronger its tensile strength and compressive strength. The yield strength of the second-grade steel bar HRB335 is 335MPa; the yield strength of the third-grade steel bar HRB400 is 400MPa; the yield strength of the fourth-grade steel bar HRB500 is not less than 500MPa.

3. Different prices: HBR335 is a second-grade steel bar, and its price is lower than the third-grade steel HBR400, while HHBR500 is known as the noble steel bar, and its price is higher than HBR400.

The main difference between a color-coated aluminum coil and a color-coated coil lies in the substrate and application field. ‌

Color-coated aluminum coil is based on aluminum, and the surface of the aluminum substrate is colored by a paint-coating process. Common ones are fluorocarbon color-coated aluminum coil and polyester color-coated aluminum coil. This material has become an ideal choice for modern building exterior walls and interior decoration due to its high strength and non-deformation characteristics. At the same time, it provides a variety of color and pattern customization services, making the building appearance more personalized and maintaining the durability and low maintenance cost of the material. ‌
The substrate of the color-coated coil is generally a cold-rolled plate, and the surface of the steel plate is coated by a coating process. Common coatings include epoxy resin, polyester, etc. The color-coated coil is widely used in construction, home appliances, and other fields due to its good corrosion resistance, fire resistance, and low maintenance cost. ‌

Color-coated aluminum coils and color-coated steel coils also have different performances. For example, color-coated aluminum coil can form an aluminum oxide film in the atmosphere to prevent further corrosion, while color-coated steel coil is prone to corrosion and rust under the erosion of humid air and rain and snow, especially at the joints.