Rebar Hrb355 Hrb400 Hrb500 8mm 10mm 12mm 14mm 16mm Ribbed bar Deformed bar Bar

1) Nominal diameter range and recommended diameter
The nominal diameter of steel bars ranges from 6 to 50mm, and the standard recommended nominal diameters of steel bars are 6, 8, 10, 12, 14, 16, 20, 25, 32, 40, and 50mm.
2) The allowable deviation of the surface shape and size of the ribbed steel bar
The design principles of ribbed steel bars should meet the following requirements:
The angle β between the transverse rib and the steel bar axis should not be less than 45 degrees. When the included angle is not greater than 70 degrees, the direction of the transverse bars on both sides of the steel bar should be opposite;
The nominal spacing l of the transverse bars should not be greater than 0.7 times the nominal diameter of the bars;
The angle α between the side of the transverse rib and the surface of the steel bar shall not be less than 45 degrees;
The sum of the gaps (including the width of longitudinal ribs) at the ends of transverse ribs on both adjacent sides of the steel bar shall not be greater than 20% of the nominal perimeter of the steel bar;
When the nominal diameter of the steel bar is not more than 12mm, the relative rib area should not be less than 0.055; when the nominal diameter is 14mm and 16mm, the relative rib area should not be less than 0.060; when the nominal diameter is greater than 16mm, the relative rib area should not be less than 0.065. See Appendix C for calculation of relative rib area.
Ribbed steel bars generally have longitudinal bars, and there are also those without longitudinal bars;