This 304 alloys material, 18Cr-10Ni, is with very low migration rate and very high durability. It has very good resistance to impact, thermal shocks, abrasion and corrosion which make it very suitable for making cookware. However the steel vessel is with poor thermal conductivity giving low energy efficiency, so it is recommended to add a thermo radiant bottom to compensate this. A thick aluminum or a copper/aluminum sandwich plate was normally applied and pressed by impact bonding - a unique process which under high temperature and pressure, form a “steel/Aluminum/steel" thermo bottom.