Food-Grade Superior Stainless Steel The Hawkins stainless steel pressure cooker body and lid are made from food-grade 18/8 non-magnetic superior stainless steel (AISI Grade 304). The '18/8' symbolises that this stainless steel grade contains 18% chromium and 8% nickel for greater anti-corrosion resistance and to better withstand the various acids found in many foods such as fruits meats milk and vegetables. It is hence one of the best quality stainless steel grades used for making cooking utensils. Type 304 stainless steel has great strength which means that properly used your Hawkins stainless steel pressure cooker will give you many years of faithful service.