GalvanisedHot dipped galvanised steel has a very heavy coating of zinc for better corrosion resistance, making it suitable for outdoor use. Because of the thick plating, only galvanised nuts and washers will fit galvanised bolts. The coating typically has a rough, dull grey finish.
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.
316 Stainless Steel316 Stainless Steel has increased corrosion resistance due to the addition of 2% to 3% molybdenum. It is suitable for marine, chemical, petrochemical, manufacturing and transport use.