Galvanized square rectangle steel tube It's a name for square pipe and rectangular pipe, which is the pipe with the same side length. It is made of strip steel after processing and rolling. Generally, the strip is unpacked, leveled, crimped and welded into a round tube, which is rolled into a square tube and then cut into the required length. Usually 50 sticks per pack. Also known as square and rectangular cold formed hollow steel, referred to as square pipe and rectangular pipe, code F and J respectively.

Product name	galvanized square rectangle steel tube
Size	10x10mm~100x100mm
Thickness	0.3mm~4.5mm
Length	1~12m as requested
Steel grade	Q195 Q235 Q355
Zinc Coating	5 micron~30 micron
Surface treatment	Galvanized/Oiled/Color painting
Further processing	Cutting/Holes punching/Welding/Bending as drawing
Package	Bundles/ Bundle with water-proof bag or as customers request
Delivery time	Normally 7-20 days after received deposit or LC
Payment term	FOB/CIF/CNF T/T & L/C at sight

1.Galvanized square rectangle steel tube, The allowable deviation of wall thickness shall not exceed positive or negative 10% of the nominal wall thickness when the wall thickness is less than 10mm, and positive or negative 8% of the nominal wall thickness when the wall thickness is greater than 10mm, except for the wall thickness of the corner and weld zone. 2.Galvanized square rectangle steel tube, The usual delivery length is 4000mm-12000mm, with 6000mm and 12000mm in the majority. Square rectangular tube allows delivery of not less than 2000mm short and irregular products, can also be delivered in the form of interface tube, but the customer should remove the interface tube when using. The weight of short and irregular length products shall not exceed 5% of the total delivery quantity, and for square rectangular tubes with theoretical weight greater than 20kg/m shall not exceed 10% of the total delivery quantity. 3.Galvanized square rectangle steel tube, The bending degree shall not be greater than 2mm per meter, and the total bending degree shall not be greater than 0.2% of the total length.

Grade	Yield Strength/Mpa	Tensile Strength/Mpa
Q195	195	315~430
Q235	235	375~500
Q345	345	490~675

Q195 Chemical Element Content
C	Mn	Si	S	P
≤0.12	≤0.50	≤0.30	≤0.040	≤0.035
Q235 Chemical Element Content
C	Mn	Si	S	P
0.12~0.20%	0.30~0.67	≤0.30	≤0.045	≤0.045
Q355 Chemical Element Content
C	Mn	Si	S	P
≤0.20	≤1.70	≤0.55	≤ 0.040	≤ 0.040

Galvanized square rectangle steel tube Theoretical weight per meter scale 4* Side length *0.00785*1.06* Thickness1, square tube production process classification Square tube according to the production process: hot rolled seamless square tube, cold drawn seamless square tube, squeeze seamless square tube, welded square tube. The welded square tubes are divided into: (a) by process -- arc welding square tubes, resistance welding square tubes (high frequency, low frequency), gas welding square tubes, furnace welding square tubes (b) by weld line -- straight seam welding square tubes, spiral welding square tubes 2. Material classification of rectangular tube Square tube according to the material: plain carbon steel square tube, low alloy square tube. General carbon steel is divided into: Q195, Q215, Q235, SS400, 20# steel, 45# steel; Low alloy steel is divided into Q345, 16Mn, Q390, ST52-3, etc. 3. Standard classification of rectangular pipe production Square tube according to production standards: gb square tube, Japanese standard square tube, British system square tube, American standard square tube, European standard square tube, non-standard square tube. 4, rectangular tube section shape classification Square tube is classified by section shape: (1) simple section square tube -- square tube, rectangular tube (2) complex section square tube -- flower shape square tube, open shape square tube, corrugated square tube, special-shaped square tube 5, square tube surface treatment classification Square tube according to the surface treatment: hot dip galvanized square tube, electric galvanized square tube, oil coated square tube, pickling square tube 6, square tube use classification Square tubes are classified according to their uses -- square tubes for decoration, square tubes for machine tools, square tubes for mechanical industry, square tubes for chemical industry, square tubes for steel structures, square tubes for shipbuilding, square tubes for automobiles, square tubes for steel beams and columns, square tubes for special purposes 7. Wall thickness classification of rectangular pipe Square rectangular tubes are classified according to wall thickness -- ultra-thick-walled square rectangular tubes, thick-walled square rectangular tubes and thin-walled square rectangular tubes