The transverse rib geometry of imported rebar is mainly ordinary square thread or ordinary oblique square thread. The transverse rib geometry of domestic rebar mainly includes spiral shape, herringbone shape and crescent shape. The order principle of rebar is generally based on the mechanical process performance or mechanical strength index on the basis of meeting the gripping performance requirements required by engineering design.

Definition: Seismic rebar is a kind of hot rolled ribbed steel bar, which is widely used in construction engineering. It is produced by small rolling mills, the production process includes the steel through high temperature pressing and other steps into hot-rolled ribbed steel bars, some of which also undergo several hours of cold working in the final stage of the process.

Logo: In the rebar symbol, such as "400E", where "E" represents seismic rebar and "400" represents grade 3 steel bar. "E" is the symbol of seismic resistance of steel rebar

Classification of steel:

First grade steel: HPB235, Q235;

Secondary steel: HRB335, HRB335E, HRBF335E;

Grade 3 steel: HRB400, HRB400E, HRBF400E;

Grade Four steel: HRB500, HRB500E, HRBF500E.

Note: The chemical composition of carbon manganese phosphorus sulfur should be indicated on the quality certificate provided by the manufacturer.