The Stainless Steel 304 is an anti-rust metal alloy, each alloy is defined with a number that specify its usability, Alloys number 304, 316, & 347, are the ones that can be used for making Cookware.
The Code 304 equals 18/10 which means:
18% is Chrome, and that’s the Alloy’s anti-rust percentage>
10% is Nickel, and that’s the percentage that gives the Alloy its shape & silver like shine, along with being partially anti-rust.