It is direct square or rectangular roll forming machine. Previously all square/rectangular tubes used be made of round tube. That means untill Weld rolls u have a round tube and after that u make square out of it... This has been changed.... What olimpia/fives and many others started doing was to directly start corner forming from the 1st pass itself... The problem with roll forming square tubes from round tubes was that it use to take more power to form and in heavier thickness it use to buckle either in coolant zone or preforming section.... (I have even seen shafts breaking and forming rolls cracking in higher T/D ratios... Also I would like to mention that in heavier thickness the post formed square happens to be so hot even after water cooling that u cannot even touch it longer with bare hand..... This was my personal experience so this may or may not happen in all old fashioned mills) With this new technology above problems are eradicated and more over the best advantage is that u can roll form square tube from a narrower strip width. For example: to make a 40x40x1.8mm tube from round tube the required strip width would be 157mm. Now, with this technology u require a much narrower strip width (atleast 2 to 3mm narrow) to make same 40x40x1.8mm square tube. Basically, in old fashioned tube Mill the thickness use to build up In the corners of final tube profile that is formed whereas with this direct forming technique the corners are preformed so it does not allow any thickness built up in the corners. Now if u would ask why would the strip width be less to form the corners then for that u need to study what k-factor is and how strip behaves when it is bent i.e. the inner radius is in compression and outer radius of strip is in tension and roughly 40% of inner radius is taken to calculate the strip width. Finally what matters most is that in lesser wastage of power and material u get a better quality material that tends to be beneficial to both-the manufacturer and the customer.