These grates are made from Type 304 food grade Stainless Steel. They are made of 1"x1"x1/8" stainless square tube frame and 3/8" stainless steel rods that are free floating for expanding and contracting. Any size made available upon request. Once you step up to a large size tubing size and rod size changes accordingly. One pic is of some stainless perforated metal that a customer requested for putting charcoals on.