A2 stainless steel A2 grade steels are the most widely used stainless steels. They are used for kitchen equipment, chemical industry appliances, fasteners and much more. Also known as 304 grade stainless steel, A2 stainless steel contains around 18% chromium and 8% nickel, giving it high corrosion resistance and good heat resistance. Padlock/locking hinge A Padlock Hinge is a hinge fitted with a locking mechanism that makes it possible to secure a door or lid. The Padlock Hinge locks the door or lid in place with a padlock, preventing unauthorised access to the protected contents.