Persberg hardware is perfect for use near saltwater, freshwater and other projects.304 stainless steel has good corrosion resistance in a bad environment like high temperature, cold weather, and high humidity areas. They have superior rust resistance and the excellent of oxidation resistance. These Hex Nuts M8 1.25 are very strong and are great for both indoor and outdoor use. The larger outside diameter perfect for applications that require a larger amount of pressure distribution such as drywall, fencing, mounting fixtures, and sheet metal. (A2-70 cold-worked Stainless Steel, also known as 18-8 or 304 Stainless Steel, 18-8 stainless steel washers have good chemical resistance and may be mildly magnetic) TOP QUALITY: Rated for both indoor and outdoor use. Superior corrosion resistance to regular plating, made with 18-8 (304) Stainless Steel. VALUE: Get the most out of your purchase! We offer different size packages so you won't have to worry about running out of hardware in the middle of your project. Persberg hardware is more corrosion resistant and stronger than other hardware and we stand by our claim 100%. SPECIFICATIONS: Diameter: 8mm 1.25 Thread Type: Coarse (standard) Quantity: 20pcs Material: 18-8 (304) Stainless Steel WARRANTY: Persberg hardware come with a 100% Satisfaction Guarantee, if you have any problems we will replace them free of charge!