Hawkins Tri-Ply Stainless Steel Patila (or Tope or Tapeli or Bhagona) retains the advantages of cooking on stainless steel surfaces while eliminating the disadvantages of sticking and burning that come with normal stainless steel. Hawkins Tri-Ply Stainless Steel Cookware is made of three layers. The Cooking Surface is made of AISI 304 18/8 food grade stainless steel that is extremely hygienic durable and non-reactive to most foods. It does not pit or corrode. The Core is made of heavy gauge aluminium which spreads heat evenly and prevents hot spots. The Base and Outer Surface is made of AISI 430 grade magnetic steel works well on gas ceramic halogen electric and induction cooktops.