Practical knowledge related with section materials

1、Category of section materials  1．Simple section steel①square steel -- hot rolled square steel, cold drawn square steel；② round steel-- hot rolled round steel, forged round steel, cold drawn round steel ③wire steel；④ flat steel；⑤ spring flat steel；⑥ angle steel -- equal-angle steel, angle steel with unequal legs；⑦ triangular steel ⑧hexagonal steel；⑨ arch steel；⑩ oval steel

2． Complicated section steel①I beam——commercial I beam, light-weight I beam②channel beam——hot rolled channel beam （commercial channel steel, light-weight channel beam）, bended channel beam③H-shape steel （also know as long-legged I beam）④steel rail——heavy rail, light rail, crane rail, other special rails⑤sash bar⑥steel sheet pile⑦bended section steel——cold bended section steel, hot bended section steel⑧Other

2、Large, medium, small size categorization of section steels

    Large size Medium size Small size

I beam Height≥ 180mm Height＜180mm  

Channel beam

Height≥ 180mm Height＜180mm    

Equal angle steel

Edge width≥ 160mm Edge width50 -140mm Edge width20 -45mm

Angle steel with unequal legs

Edge width≥160× 100mm Edge width140×90-50× 32 mm

Edge width≤45× 28 mm

Round steel Diameter ≥ 90mm Diameter 38 -80mm Diameter 10 -36 mm

Square steel Edge width≥ 90mm Edge width50 -75 mm Edge width10 -25 mm

Flat steel Width ≥ 120mm Width 60 -100 mm Width 12 -55 mm

Threaded steel

   Diameter ≥ 40 mm Diameter 10 -36 mm

Rivet steel          Diameter10 -22 mm

Other Shaped steel：caterpillar block, and steel sheet pile, etc.

Shaped steel, composite flat steel for small-sized agricultural tools, etc.

Shaped steel, agricultural steel, and sash bar, etc.

3、Hot rolled ribbed bar  1．Categories and specificationThe hot rolled ribbed bars have steel numbers composed of HRB and the value at the minimum yield point. H, R, and B stand for Hot rolled, Ribbed, and Bars, respectively. Hot rolled ribbed bars have 3 steel numbers: HRB335（original steel number is20MnSi）, HRB400（original steel numbers are 20MnSiV, 20MnSiNb, and 20MnTi）, and HRB500.  2．Vanadium grade Ⅲ threaded steel bar①Vanadium grade Ⅲ threaded steel bar has a prominent marketAlloys such as vanadium, niobium, and titanium, etc. are added during the production of vanadium grade Ⅲ new threaded steel bar（20MnSiV, 400Mpa）. Compared with commercial grade Ⅱ threaded steel bar, the vanadium grade III threaded bar has such advantages as high strength, strong toughness, good welding performance, and good seism resistance, etc.. In the construction market in developed nations in Europe, the market share of grade Ⅲ threaded bar accounts for 80% of the total market share of the threaded bar, e.g., percentage of vanadium grade III threaded bars used has reached 80-90% in such nations as UK, Germany, Australia, and Japan, etc.. In 1995, the former department of metallurgy, together with the department of construction of China, expressed their demands explicitly in a document for the industry to use this type of bars. The department of construction added the technical requirement of new grade III threaded bar into the “specifications of concrete structural design” of National standard GBJ10-89, which has been in effective since Jan. 1, 1997. Nowadays, the new grade III threaded bar has been successfully applied in the construction projects including high buildings, large-sized power stations, bridges, tunnels, and airports, etc., which shows the future of the market is very prominent. The department of construction required that the use of the new grade III bar should account for 50% of the total threaded bar consumption by the end of 2002, and that 80% by the end of “the 10th five-year plan”. However, due to the non-sufficient media and advertising work, the use of new bar is much lower than the consumption of the old grade II commercial threaded bar. Therefore, much more work of media and advertising work should be done for the new grade III threaded bar.    ② Advantages of vanadium grade III threaded barA.Cost effective: Because the strength is higher, using new grade III threaded bar can save 10-15% steel compared with using grade II bar，and this will result in reduced construction cost for the project. B.The strength is high, and the toughness is good: It is treated by micro alloy treatment technology, and the yield point is above 400 Mpa and tensile strength is above 570 Mpa, which are 20% higher than those of grade Ⅱ bar. C.Anti seism：the vanadium bar has high bending resistance, good aging resistance, and good low-cycle fatigue performance; therefore, its seism resistance is significantly superior to that of the grade II bar. D.Easy for welding： the carbon content is ≤ 0.54%，therefore, the welding performance is good. It can be adapt for all kinds of welding methods, and the technique is simple and easy. E.Easy for construction: The use of new grade III threaded bar can increase the construction intervals, therefore, it is more convenient for construction, and it is easier to guarantee the construction quality.

4、Hot rolled H shaped steel1． Methods for denoting hot rolled H shaped steelH shaped steel can be divided into three types: wide-flanged H-shaped steel（HK）, narrow-flanged H-shaped steel（HZ）, and H-shaped steel pile（HU）. The denoting method is: height H × width B × web plate thickness t1 × wing plate thickness t2，e.g., H shaped steel Q235, SS400 200×200×8×12 stands for wide-flanged H-shaped steel with height of 200 mm, width of 200 mm, web plate thickness of 8 mm，and wing plate thickness of 12 mm，with steel number of Q235 or SS400.

2． Advantages of hot rolled H-shaped steelH-shaped steel is a new type of cost effective construction steel.H-shaped steel has reasonable and cost effective sections and good mechanical properties. During the hot rolling, every point on the section extended uniformly, which result in low internal stress. Compared with commercial I beam, hot rolled H-shaped steel has such advantages as large section modulus, light weight, and material sparing. Using H beam can decrease the weight of construction structure by 30-40%; the inner edge of the leg is parallel to the outer edge, and the leg end is right angled, as a result, it is easy to be

assembled into elements, therefore, the welding and riveting work can be reduced by up to 25%. It is often used for large scale construction work (such as factories, high buildings, etc.), bridge, ship, crane, transportation vehicle, foundation of equipments, frame, and foundation pile, etc., which require good bearing capacity and stable sections.

5、Cold bended section steel

Cold bended section steel is a cost effective section light-weight thin-walled steel material, also referred to as steel cold bended section material, or cold bended section material. It is section steel with different section shapes and dimensions, which is produced by bend forming the ingot made of hot rolled or cold rolled steel strip. The cold bended section steel has the following characteristics:  1． The sections are reasonable and cost effective, therefore, good for saving materials. It is possible to design the section shapes of cold bended section steels according to requirements. It has a reasonable structure, and the section coefficient per unit weight is higher than that of hot rolled section steel. Under the same load, using cold bended section steel can reduce the weight of components, and save materials. Compared with using hot rolled section steel, using cold bended section steel can save 38-50% metal materials for construction structures, and 15-60% for agriculture equipments and vehicles. It is convenient for construction, and the total cost can be reduced.2．Many types of cold bended section steel is available, and it is possible to produce all kinds of section steels with uniformed wall thickness and sophisticated section shapes, as well as cold bended section steels with different materials, which is otherwise difficult to produce by usual hot rolling methods. 3．The product is with shining clean surface, good appearance, and precise dimensions, and it is possible to produce products with different lengths according to requirements. In order to improve the material yield, it is supplied according to the designated size, or several folds of the designated size.4．It is also possible to combine other procedures such as punching into the production process, in order to meet different requirements.

There are many categories of cold bended section steel. By section shapes, it can be divided into: open, semi-closed, and closed. Main products include: cold bended channel steel, angle steel, Z-shaped steel, cold bended corrugated steel plate, square pipe, rectangular pipe, electrically welded shaped pipe, and roller shutter door, etc. Usually the produced cold bended section steel has a thickness below 6 mm and a width below 500 mm. The products are widely used for the industry of mining, construction, agricultural equipments, transportation, bridge, petro-chemical engineering, light industry, and electronics, etc.

Source : http://www.east-steel.com/09.htm