Lock Washers provide a locking spring action and prevent fasteners from loosening due to vibration. They are used with a bolt or screw to evenly spread the load over a wider area. Use stainless steel where corrorsion is and rust is of concern or in exterior applications. Best for general hardware use or where high strength is not required. Diameter: 1/4 inch Thickness: 0.062 Inside Diameter: 0.260 inch Outside Diameter: 0.487 inch Material: 18.8 Stainless Steel