GB/6278 Welded Square Tube

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20 m.t.
Supply Capability:
15000 m.t./month

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Product Description:

1Structure of GB/6278 Welded Square Tube:

ERW steel pipe is electric resistance welding, the abbreviation for ERW for transporting oil and natural gas vapor liquid objects, can meet the requirements of high and low pressure, the transport in the world with pipe sector accounted for a pivotal position.


2‍‍Main Features of GB/6278 Welded Square Tube:

• High manufacturing accuracy

• High strength

• Good visual effect

• Reasonable price  

• Small inertia resistance

• Strong heat dissipation ability


3GB/6278 Welded Square Tube Specification



ASTM A106-2006, ASTM A53-2007


10#-45#, 16Mn

10#, 20#, 45#, 16Mn


1 - 33 mm

Section Shape


Outer Diameter

21 - 610mm

Place of Origin

Tianjin, China (Mainland)

Secondary Or Not



Hydraulic Pipe


Cold Drawn



Surface Treatment

factory state or painted black

Special Pipe

API Pipe

Alloy Or Not




Outer Diameter



20#, 45#, Q345, API J55, API K55, API L80, API N80, API P110, A53B




1) Material:20#(ASTM A 106/A53 GRB.API5LGRB,GB),45#,16Mn,10#.

2) Specification range:OD:21.3-610mm,WT:6-70mm,length:6-12m or according to the requirement of clients.

3) Excutive standards:GB,ASME API5L.ASTM A 106/A53,Despite of the above standards,we can also supply seamless steel pipe with standard of DIN,JIS,and so on,and also develop new products according to the requirements of our clients!
4) Surface:black lacquered,varnish coating or galvanized.
5) Ends:Beveled or square cut,plastic capped,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 GB/6278 Welded Square 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.



GB/6278 Welded Square Tube 

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Q:What are the advantages of membrane switch series?
1. Folding membrane switch. It is usually printed the pattern symmetrical in the upper and lower circuit on the same side of the membrane, and folded along the graphical symmetry axis to form the upper and lower circuit which constitutes corresponding contact of a set of switches keyboard under the action of the spacer layer. This is called folding circuit. 2. Double-plate membrane switch. It is printed two contacts of a set of switches, and wires and leads of the switch contact on two membranes respectively, constituting the upper and lower circuit of the switch. The double-chip circuit, for its lead is not folded, overcomes some of the defect of the folding circuit.
Q:Water is the water base wallpaper wallpaper glue?
Water is the water base wallpaper wallpaper glue? It is a professional alkali resistant, moistureproof, mouldproof wall treatment materials, can effectively prevent the construction of the base surface of the tidal water and alkaline material extravasation, avoiding of wall decoration materials: Such as wallpaper, paint, plywood, decorative board, damp moldy black bad damage.
Q:Which is better between electric hot plate and electrothermal film?
It depends on actual situation, which can not be directly determined which one is good. The electrothermal film is a kind of exothermic material made of special conductive macromolecule material matched with metal current-carrying strip, hot melted between the insulating film bodies, which will produce heat after being electrified Mainly used for heating element. The electric hot plate is equippment taking electric heating alloy wire as heating material, and mica soft board as insulating material, and wrapping thin metal plate (aluminum plate, stainless steel plate, etc) in the surface for heating. Typical applications like electric hot water bottles. Casting metal tubular electric heating element in aluminum plate/aluminum plate or welding or inlaying on the aluminum plate/aluminum plate to form electrical heating plate of all shapes. Typical application like electric cookers, electric irons, electric coffee makers, etc.. ! ~
Q:What is a thin-film solar?
The solar photovoltaic panels are divided into two kinds, the crystalline silicon and amorphous silicon. The thin film amorphous silicon is one of the solar panels. The advantages of crystalline silicon solar cells: The technology is mature and the per unit area conversion efficiency is high(15% -19%); Disadvantages: The low light property is poor so it can only be made in fixed shape. The advantages of the amorphous silicon solar cells: The low light property is strong, and it can be made into any shape, especially for BIPV; Disadvantages: The technology is not mature, and the per unit area low conversion efficiency(up 9%) is low.
Q:What does geomembrane PE mean?
PE is polyethylene, HDPE is high density polyethylene
Q:Which is better, oil heater or electrothermal film
Electric heater is also called electric heater with oil charge. The electric heater is filled with a new type of heat conducting oil, when the power supply is switched on, the heat conducting oil around the electric heating tube is heated, and then the heat is distributed along the heat pipe or the scattered piece. electrothermal film electric heater uses all transparent high temperature electrothermal film as the heating material, it is the advanced level in the process in the world.
Q:the seepage-proof pavement of composite geomembrane.
After laying, there is no major changes, it has high tensile strength and elongation .9m, paving, two cloth one film. after waving and combination.1 it has listed the main performance of products Hunan Vinylon plant produced more than .5 indicators. ④ protective layer and surface protection against geomembrane 10cm thick protective layer soil material must be sieved to influence the choice of reference .3, storms and other factors for the design and material of scour protection layer of soil to withstand an external force. Domestic and international application of impermeable plastic film. In order to prevent storm and water from bringing away the dam shell protective layer clay particles, such as the former Soviet Union BCH07-74 "Notice for the earth-rockfill application of polyethylene dam seepage control structure". Particle diameter of the protective layer should not be too large, before finishing the pavement of packaging layer, seepage-proof film composite geo-membrane takes plastic film as the seepage-proof base material, but without bubble in the bottom, seam width is 50mm, seal the seepage stream entrance, the yarn will concentrate on the cracks open. For security, the ramp design is 1, laying area should not be too large,and is easy to blow by the wind; p-- withstand the maximum head, they have good bacteria and chemical erosion resistance.
Q:How to remove the heating film in the fish tank?
Heating rods can stick out the water surface. The temperature knob and wire part has been sealed, so there will be no leakage. If you see there is water vapor in the heating pipe, it does not matter, because that is the water vapor sealed in the tube. This vapor exists because it is difficult to achieve complete vacuum in domestic products. Instead, if you do not put all the heating rods into the water, the water will be unevenly heated. When the part out of the water is cold and the part inside of the water is hot, heating rods will crack, especially at the seal. By then, the water will flow into the rods causing water leakage.
Q:Who knows the repair method of membrane switch?
It can only be tested with the help of schematic circuit of the membrane switch. It is usually the shift knob that goes wrong. If there is no schematic circuit, you can only find out the problem by yourself. Membrane switch is actually a trigger signal to the IC. It is mostly a line or an array. This problem is rather obvious and easy to find out, but generally when membrane switch goes wrong, there is no way to repair but switch to a new one.
Q:How to use 3M light box film?
There are many kinds of light box film, colored semi transparent film, uniform light film, light blocking film, double color film, etc. Color semi transparent film is the most commonly used. There are many colors for you to choose. Customize colors according to customers' demand. Make back lighting display board by cooperating with soft lamp-box fabric. The construction method of film sticking is divided into: Dry paste method and wet paste method. It depends on different products.

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