Square tube , called a square tube. After treatment process is roll formed . 

Generally is unpacking , rolling, tube welding , and then rolled into the square tube, 

then cut into the required length. The density of steel is : 7.85g / cm3.

Various specifications can also be customized according to user requirements .
1 . Executable GB6728-2002 cold-formed structural hollow sections standards.
2 . Executable JISG3466-88 Japanese general construction Rectangular Pipe 

adapt the scope of the standard .
3 . Other special precision to sign the agreement by both.

500*500*8~25 220*220*8~25 130*130*4~12

450*450*8~25 200*200*8~25 120*120*4~12

400*400*8~25 180*180*7~20 110*110*4~12

350*350*8~25 160*160*5~16 100*100*4~12

300*300*8~25 150*150*5~14 80*80*4~12

280*280*8~25 140*140*4~14 60*60*4~12

250*250*8~25 135*135*4~14 50*50*4~12

40*40*4~10 30*30*.~6 20*20*2~4