1These hex nuts are made of 304 stainless steel which provides strength and offers good corrosion resistance in many environments. 2Hexagonal shape has 6 sides that gives a good granularity of angles for a tool to approach from. 3These are many common sizes that you can use for general purpose or projects. 4These hex nuts will be great replacement for industrial and construction fasteners. 5Used widely in the home and office appliance, communication equipment, ship assembly and other machinery industry.