1, round steel representation: a circle with vertical lines or diagonal lines is round steel, that is, first-class steel;
2. Representation of rebar: A circle with a vertical line and then a horizontal line below the vertical line is rebar, which is secondary steel, and a circle with a vertical line and then two horizontal lines below the vertical line is rebar, but the level is one level higher, which is tertiary steel.
Rebar should be properly named: ribbed steel bar, and its code name is abbreviated as HRB in English. At the same time, according to the characteristic value of yield strength, it is divided into HRB335, HRB400 and HRB500, which should be noted when labeling. When drawing round steel, the diameter and material should be indicated, such as ￠35/ material Cr 12.
Extended data:
First of all, there are two commonly used reinforcement classification methods:
1, classified according to geometric shape, classified or classified according to cross-sectional shape of transverse ribs and rib spacing. For example, in British Standard (BS4449), steel bars are divided into type I and type II. This classification mainly reflects the grip performance of steel bars.
2. Classification by performance (grade), for example, according to the current implementation standards in China, rebar is (G B 1499.2-2007), wire is 1499. 1-2008), and rebar is classified by strength grade (yield point/tensile strength). Japanese industry standard (Ji SG3 1 12).
According to comprehensiveness, rebar can be divided into five categories; British Standard (BS446 1) also stipulates several grades of steel bar performance test. In addition, steel bars can also be classified according to their uses, such as ordinary steel bars for reinforced concrete and heat-treated steel bars for prestressed reinforced concrete.
Steel bars are widely used in civil engineering construction such as houses, bridges and roads. From highways, railways, bridges, culverts, tunnels, flood control, dams and other public facilities to the foundations, beams, columns, walls and slabs of buildings, steel bars are indispensable structural materials. With the deepening of urbanization in China, there is a strong demand for rebar with the vigorous development of infrastructure construction and real estate.
Second, the round steel classification:
1, classified by process
Round steel is divided into hot rolling, forging and cold drawing. The specification of hot-rolled round steel is 5.5-250 mm, of which small round steel of 5.5-25mm is mostly supplied by bundled straight steel bars, which are often used as steel bars, bolts and various mechanical parts.
Round steel larger than 25mm is mainly used for manufacturing mechanical parts, seamless steel pipe blanks, etc.
2, according to the chemical composition classification
Carbon steel can be divided into low carbon steel, medium carbon steel and high carbon steel according to chemical composition (that is, carbon content).
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