Difference between these 2 types of box section? SHS ERW

[visor_down]

Hi

Can anyone explain the difference in specification between these two types of box section, the pros and cons of each and why you would choose one over the other?

25 x 25 x 2.0 S235JRH CF RED - Square Hollow Section
http://www.parkersteel.co.uk/Product/63827/Square+Hollow+Section/25+x++25+x+2.0+S235JRH+CF+RED


25.0 x 25.0 x 2.0 EN10305 E220 - ERW Square Semi-Bright Tube
http://www.parkersteel.co.uk/Produc...mi-Bright+Tube/25.0+x+25.0+x+2.0+EN10305+E220

Cheers
visor_down

 

[bigegg]

I *think* the main difference is that SHS has a pronounced seam on the inside, and will have mill scale.
ERW won't

 

[nickk]

the shs has bigger radii & a more pronounced weld seam on the inside & is a 7.5m length,the erw will be oily yet grey/silvery underneath & comes in 6m bars.