Steel structured building uses SM570 has already become a trend of the future since the construction of Taipei 101. Due to better welding technology and popularized welding material, structural design has been expand and elevate to a whole new level. Nowadays there are more and more high rise or large-span buildings use SM570, especially since 2014, the application shows a significant increase. DSC’s SM570 formed steel and Flats have been applied to our own indoor warehouse (with span 142m) and buildings in Taipei, Kaohsiung and Hualien, our products provide stable quality which our customers deeply rely on. SM570 is a strength of 60kgf grade steel which possess excellent low temperature toughness, provides advantages in material saving, weight reducing and optimize available spaces, especially for high rise buildings and large-span truss structural engineering. Our Flat has CSC SM570M specification (seismic design of high strength structural steel), and just like SN steel, we added physicochemical requirements such as carbon equivalent limit, narrow yield strength, upper limit of yield ratio, through-thickness characteristics contraction, and guarantee of UT JIS G0901 to ensure its material weldability and seismic toughness.