Construction Material Q235 Black Welded Tubular Steel

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1Construction Material Q235 Black Welded Tubular Steel:

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 Construction Material Q235 Black Welded Tubular Steel:

• High manufacturing accuracy

• High strength

• Good visual effect

• Reasonable price  

• Small inertia resistance

• Strong heat dissipation ability


3Construction Material Q235 Black Welded Tubular Steel 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 Construction Material Q235 Black Welded Tubular Steel: 

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 Welded Black ERW Steel Pipe Images ‍‍

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Q:Are the welded and galvanized tubes the same weight?
There should be no difference in the weight of the same specifications for the welded pipe and galvanized pipe. The slight difference is that the galvanized pipe should be pickled before galvanizing and must digest some iron and then galvanized. The difference depends on the difference in the process. So the theoretical calculations are the same.
Q:Seamless steel pipe is how to do it?
Seamless steel tube is a kind of steel strip with hollow section and without seams. A steel pipe having a hollow cross section, used as a conduit for conveying fluids, such as pipelines for transporting petroleum, natural gas, gas, water, and certain solid materials. Compared withsteel and roundsteelinsolid, flexural torsional strength in the same time, the weight is light, is a kind of economic section steel, widely used in the manufacture of structural parts and mechanical parts, such as the oil pipe, automobile transmission shaft, the bicycle frame and steel construction with scaffold. The manufacture of ring parts with steel tubes can improve material utilization, simplify manufacturing processes, save materials and work hours, such as rolling bearings, rings, Jack sleeves, etc., and have been widely used in steel pipes. Steel pipe or all kinds of conventional weapons indispensable materials, gun barrels are made of steel. The steel pipe can be divided into round tube and special-shaped pipe according to the sectional area shape. Because the circle area is the largest under the condition of equal circumference, more fluid can be transported with round tubes. In addition, the ring section in the internal or external radial pressure is more uniform force, so most of the steel pipe is round tube.
Q:How long are the seamless tubes? Are they six meters long?
6 meters of a root in general need to be customized, seamless tubes are mostly seven meters above the variable foot
Q:What quota is reserved for buried DN20 steel pipe?
It is an embedded sleeve control sub item, if the reserved hole, then there is no need to cover, special subject structure adjustment factor of the cost of the water supply and drainage engineering, water supply and drainage engineering he is buried under the charge.
Q:What does cathodic protection of steel tubes mean?
The corrosion of metals causes great economic losses directly or indirectly. Foreign statistics show that every year due to corrosion and scrap metal materials, equivalent to 20~40% of metal production, the world every year due to corrosion and loss of metal reached more than 1 tons.
Q:What are low-pressure carbon steel tubes?
It's pressure levelThe design pressure (P) of pressure vessel is divided into four pressure levels: low voltage, medium pressure, high pressure and extra high pressure:(1) low voltage: Code L, 0.1MPa is less than or equal to p<1.6MPa(2) MP: Code M, 1.6MPa is less than or equal to p<10.0MPa(3) high voltage: Code H, 10.0MPa is less than or equal to p<100.0MPa(4) high voltage: Code U, P = 100.0MPa
Q:20# seamless steel pipe and seamless steel pipe 20G what is the difference?
The difference is: 20# ordinary steel seamless steel pipe. 20G is the type of steel for high pressure boiler tubes.
Q:What is the process of spiral steel tube production?
1. open panel inspection: after the steel plate is opened, the product line is entered, and the ultrasonic examination of the whole plate is carried out first.2., flat milling: through the anvil machine to make the original coiled steel flat, and then through the milling machine on the edge of the steel plate two sides milling, so as to achieve the required plate width, plate edge parallelism and groove shape.
Q:How big is the seamless steel tube of DN50?
This refers to the diameter of the steel pipe is 50 mm, DN50 steel pipe diameter is 60.3 mm, that is, 60.3 * 5 mm steel pipe
Q:What does "SC50" steel pipe mean in civil engineering?
SC50: laying on welded steel tubes of diameter 50mm. SC is usually used in electrical installation drawings.

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