National standard square rectangular tube

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15 m.t.
Supply Capability:
9800 m.t./month

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Item specifice:

Standard: GB,EN Technique: Hot Rolled,Cold Rolled,Cold Drawn,ERW,EFW Shape: Square,Rectangular
Surface Treatment: Galvanized,Oiled,Black Steel Grade: Q195,Q215,Q235,Q215B,Q235B Certification: CE
Thickness: 0-25 Length: 0-18 Net Weight: 0-10

Product Description:

1Structure of  National standard square rectangular tube: 

Square tube, square tube is a kind of call and rectangular tube, is equal and not equal to the length of steel pipe. Is the strip through the process of processing roll system. In general is the strip through the demolition of the package, flat, curly, welded to form a circular tube, and then rolled into a square tube and then cut into a square tube and then cut into the required length.


2‍‍Main Features of  National standard square rectangular tube:

• High manufacturing accuracy

• High strength

• Small inertia resistance

• Strong heat dissipation ability

• Good visual effect

• Reasonable price 


3 National standard square rectangular tube Specification




10#-45#, 16Mn

10#, 20#, 45#, 16Mn


1.5 - 25 mm

Section Shape

Square  and rectangular

Outer Diameter

20*20 mm-------400*400mm   20*30mm*300*500mm

Place of Origin

Tianjin, China (Mainland)



Outer Diameter

20*20 mm-------400*400mm   20*30mm*300*500mm


235B   345B 




1) Material:(ASTM A 106/A53 GRB.API5LGRB,GB,235B,345B

2) Specification range:OD: 20*30mm----300*500mm 20*20 mm---400*400mm    ,WT: 1.5 - 25 mm   ,length:3-12m or according to the requirement of clients.

3) Excutive standards:GB,ASME API5L.ASTM A 106/A53,Despite of the above
4) Surface:black lacquered,varnish coating or galvanized.
5) Ends:Beveled or square cut ,painted.
6) Packing:bundles wrapped with strong steel strip,seaworthy packing. 



4Packaging & Delivery

Packaging Details:

seaworthy package,bundles wrapped with strong steel strip

Delivery Detail:

15-30days after received 30%TT


5FAQ of  National standard square rectangular tube:  

How is the quality of your products?
    Our products are manufactured strictly according to national and internaional standard, and we take a test 
on every pipe before delivered out. If you want see our quality certifications and all kinds of testing report, please just ask us for it.
Guaranteed: If products’ quality don’t accord to discription as we give or the promise before you place order, we promise 100% refund.

How about price?
    Yes, we are factory and be able to give you lowest price below market one, and we have a policy that “ for saving time and absolutely honest business attitude, we quote as lowest as possible for any customer, and discount can be given according to quantity”,if you like bargain and factory price is not low enough as you think, just don’t waste your time.Please trust the quotation we would give you, it is professional one.

Why should you chose us?
    Chose happens because of quality, then price, We can give you both.Additionally, we can also offer professional products inquiry, products knowledge train(for agents), smooth goods delivery, exellent customer solution proposals.Our service formula: good quality+good price+good service=customer’s trust
SGS test is available, customer inspection before shipping is welcome, third party inspection is no problem.


6‍‍ National standard square rectangular tube Images ‍‍

National standard square rectangular tube

National standard square rectangular tube



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Q:Water, gas, steel pipes, thick steel wire means?
Water pipes, gas pipes and other collectively known as water gas pipe, generally galvanized steel pipe, so it can be called water and gas pipe. Most of them are welded steel tubes made of low carbon steel.
Q:Can the KBG25 steel tube hold 4 six types of cables?
1 of the six lines of cross-sectional area of about 25 square millimeters, 4 to 100 flat, KBG25 cross-sectional area of about 490100/490=20.4%, just over the specifications, so short distance and less elbow can be worn. However, due to the construction of pipes are generally not standardized, elbow more, and do not use special elbow (site bending), so KBG25 wearing 4, six kinds of cable are more difficult.
Q:What are the uses of welded steel pipes?
It is used to transport water, gas, air, oil and heating steam, and generally lower pressure fluid and other purposes of welded steel pipe. The wall thickness of the steel pipe is divided into ordinary steel pipe and thickened steel pipe. The end of the pipe is divided into non - threaded steel pipe (light pipe) and threaded steel pipe. The specification of steel pipe is expressed by nominal caliber (mm). The nominal diameter is the approximate value of the inner diameter. Usually used in inches, such as 11/2. The welded steel pipe for low pressure fluid transportation is used as the main pipe of galvanized steel pipe for low pressure fluid transportation except for directly conveying fluid
Q:What does GALV mean in a steel tube?
Steel pipe is not only used to transport fluid and powder solid, exchange heat energy, and manufacture mechanical parts and containers, but also is an economic steel. It can reduce weight and save 20 to 40% of metal by using steel pipe to make building structure, network frame, prop and mechanical support. Moreover, it can realize factory mechanization construction. Using steel pipe to manufacture road bridge can not only save steel, simplify construction, but also greatly reduce the area of coating protective layer, save investment and maintenance cost.
Q:What are the lengths of scaffold steel tubes?
Scaffold tubes are our name for materials used to build scaffolding, because most scaffolding uses tubular bamboo or steel tubing. Bamboo and other bamboo is for a long time in the use of the scaffolding tube, but due to lack of safety and durability, now only in rural and urban area construction is lagging behind some of the home building small building has been used. The modernization construction, the most commonly used type of scaffolding pipe is steel pipe, the scaffolding should not only meet the demand of workers, but also to meet the characteristics of scaffolding firm and durable, so tough hard steel is the best choice. The selected steel pipe generally requires smooth surface, no cracks, no bending, no rust, and meet the relevant national standards.
Q:Can galvanized steel tubes simmer?
I make the steel pipe, galvanized pipe and water conveying pipe material is the same, can be bent, specific to what to look at the furnace, can refer to a single material
Q:How to make the internal tooth of the steel pipe?
Compared with the ordinary light pipe, tube can effectively prevent the formation of steam film between the seal and the pipe wall, increase the light disturbance flow inside the tube, the tube wall temperature is more uniform, which can avoid the light pipe damage, and improve the heat transfer efficiency of boiler. The number of thread head of internal thread pipe is 4, 6 head and 8 head according to need. The main materials are 20G, SA210C, T2, T12, 12Cr1MoVG, 15CrMoG, T22, T23 and so on. China needs 2.5~3.0 tons per year of inner thread tube.
Q:Where is the difference between seamless steel pipe and welded pipe?
The steel tube is a hollow steel strip, used as pipe conveying fluid, such as oil, gas, water, gas, steam, in addition, the bending and torsional strength of the same, the weight is light, so it is widely used in the manufacture of machinery parts and engineering structures. It is also used to produce all kinds of conventional weapons, guns, shells and so on.Pipe classification: steel pipe seamless steel pipe and welded steel pipe (tube) two categories. It can be divided into round tube and special-shaped tube according to the sectional shape. The round steel tube is widely used, but there are some special-shaped steel tubes such as square, rectangle, semicircle, hexagon, equilateral triangle and octagon.
Q:Can seamless steel pipe and ordinary steel pipe be welded?
If your project is a seamless steel pipe, so theoretically, you put the tube with connected is not used.But the actual engineering operation, design drawings will be put on the normal need to improve the requirements of the drawings to the actual requirements, so if is the need of seamless steel pipe, welded pipe in the end so can you see yourself.
Q:What does "steel pipe SC" mean?
DN100 and "SCH80" refer to the outer diameter and the wall thickness of the steel pipe;

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