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I am planning to use stainless steel angles as brick ledge support. Location is Chicago area. Is A304 a good choice?
A304? If you are referring to ASTM A304, that’s not stainless steel. There are generally two grades of 304 stainless steel…304 and 304L, with the “L” designating lower carbon content. These are also generally known as 18-8 stainless steels, referring to their Chromium and Nickel contents respectively.
Both have good corrosion resistance but can be pitted by caustic materials (mortar is caustic initially, but moderates rather quickly to a reasonable pH.
304, 308, or 316 stainless steels are acceptable for your application. In structural angle, you might not have a lot of choice of availability.