A nut with a built in washer like flange.
ZincA low carbon steel for general use. Zinc plating provides a moderate corrosion resistance suitable for indoors or otherwise dry conditions. Colour is either a blue-ish tint or yellow depending on the exact process utilised during manufacture.
304 Stainless Steel304 Stainless Steel composition is 18% chromium and 8% nickel. When working with 304 Stainless Steels, it is recommended that stainless tools are used. This avoids cross contamination of stainless by easily corroded metals.