I think 3 16 stainless steel is better than 304 lunch box.

1. Material composition and corrosion resistance

3 16 stainless steel has more rare element molybdenum (Mo) than 304. The corrosion resistance, oxidation resistance and high temperature resistance of 3 16 stainless steel are much stronger than 304.

2. Density and hardness

The density of 3 16 stainless steel is 8.03g/cm^3, and that of 304 stainless steel is 7.93g/cm^3.

3. Price and use

304 stainless steel is generally only used for daily utensils, such as pots and pans, while 3 16 stainless steel is mostly used in medical, mechanical and other industries, and there are also some edible utensils.