About this itemStainless steel 304(18-8) which is advanced to regular steel and any zinc plated fasteners, high hardness, corrosion resistance, can be used in humid environments, and don't worry about rust.Nuts Type : Serrated Flange Hex Lock NutsInside Diameter: 1/4 Inch; Thread Size: 20 Threads according to Inch.Package Included: 50PCS Serrated Flange Hex Lock NutsHigh visitor satisfaction, when you are now not satisfied with the product, you could possibly constantly ship us an email, present you with passable