SS400 Square and Rectangular Hollow Section

SS400 square tube, as the name suggests, is a kind of material of many kinds of materials that can form a square tube body. Generally, the strip steel is unpacked, flattened, rolled to the required size, and welded to form it. The length can be determined according to the needs. Commonly used meters are 6 meters and 12 meters, and the number of packages depends on the diameter of the square tube. In terms of spot, square pipes are mostly in large specifications ranging from 10*10*0.8-1.5~~500*500*10-25. The use of square pipes is structural square pipe, decorative square pipe, construction square pipe, mechanical square pipe, etc.  We manufacture Square and Rectangular Hollow Sections over 10 years, with good reputation. We exported 1000-5000tons to Africa,UAE,Pakistan,ect…every year. Welcome to visit us, pls send your inquire if necessary.

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1. Classification of SS400 Square /Rectangular hollow sections production process
Square hollow/ Rectangular hollow is divided into: hot-rolled seamless square tube, cold drawn seamless square tube, extruded seamless square tube, welded square tube.
The SS 400 welded square tube is divided into:
(A) According to the process-arc welding square tube, resistance welding square tube (high frequency, low frequency), gas welding square tube, furnace welding square tube
(B) According to the weld seam-straight seam welded square pipe, spiral welded square pipe
2. Material classification of square tube
square tube/rectangular tube is divided by material:
Plain carbon steel square tube, low alloy square tube. Common carbon steel is divided into: Q195, Q215, Q235, SS400, 20# steel, 45# steel, etc.; low alloy steel is divided into Q345, 16Mn, Q390, ST52-3, etc.

3. Standard classification of square hollow /rectangular hollow production
SS400 Square pipes /Rectangular pipes are divided into production standards: national standard square pipe, Japanese standard square pipe, British standard square pipe, American standard square pipe, European standard square pipe, and non-standard square pipe.
4. The shape classification of square pipe section
Square pipes are classified according to the shape of section:
(1) Simple section square tube-square square tube, rectangular square tube
(2) Square pipe with complex cross section-flower-shaped square pipe, open square pipe, corrugated square pipe, special-shaped square pipe

Classification of square tube surface treatment
Square tube/Rectangular tube is divided into surface treatment:
Hot-dip galvanized square pipe,
Electro-galvanized square pipe/rectangular pipes, oil-coated square pipe, pickling square pipe
6. Classification of square tubes
Square pipes/rectangular pippes are classified by purpose-square pipes for decoration, square pipes for machine tools, square pipes for machinery industry, square pipes for chemical industry, square pipes for steel structures, square pipes for shipbuilding, square pipes for automobiles, square pipes for steel beams and columns Tube, special purpose square tube

Product Type EN-10025-2 Grade SS400 Rectangular Hollow Section
Specification OD15*15mm-400*400mm
OD 15*15-400*400mm, WT0.8-12.0mm
Wall Thickness 0.8~12.0mm
Standard GB, BS, ASTM
Steel material Q195. Q215, Q235, Q345
Size length 15mm-400mm, WT: 0.313mm
Surface Treatment Bared, Black Painted (varnish coating), Galvanized, With Oiled, 3 PE, FBE, corrosion resistant coating
Section Shape Square and rectangular
Package Bundle, In Bulk, Bags square galvanised steel hollow section tube, Clients’ Requirements
Equivalent Grade of SS400 Square Tubes
USA Germany
European old
St 44-2
SS400 E28-2 161-430
Fe430B AE295B AE255B
Chemical Properties of SS400 Square Tubes
max 0.22
max 1.5
max 0.04
max 0.04
max 0.012
max 0.55
max 0.42
Mechanical Properties of SS400 Square Tubes
Minimum yield strength Reh
Tensile strength Rm
Minimum elongation – A
Lo = 5,65 * √So (%)
Notch impact test
Steel grade Nominal thickness
Nominal thickness
Nominal thickness
Temperature Min. absorbed energy
≤16 >16
°C J
SS400 275 265 255 245 235 225 410-560 400-540 23 22 21 19 +20 27

SS400 Rectangular and Square Hollow Section Specifications:

Square & Rectangular Steel Pipe Size Chart
Square Hollow Section Rectangular Hollow Section Thickness
10*10  20*20  25*25  30*30 10*20 20*40  30*40 1.2-3.0
40*40  50*50 30*50  25*50  30*60  40*60 1.2-4.75
60*60 50*70  40*80 1.2-5.75
70*70  80*80  75*75  90*90  100*100 60*80  50*80  100*40  120*80 1.5-5.75
120*120  140*140  150*150 160*80  100*150  140*80  100*180  200*100 2.5-10.0
160*160  180*180  200*200 200*150  250*150 3.5-12.0
250*250  300*300  400*400  450*450  350*350 250*200  300*200  350*200  350*250  450*250  400*300  500*200 4.5-15.75
400*400  500*500  550*550  600*600 400*350  400*250  500*250  500*300  400*600 5.0-20.0


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