I am building a 6 sign billboard, but the customer wants to use a 3/16 wall steel pipe. My engineer can't find any structural specs on the pipe, 4" 5" and 6", it doesn't matter if that is OD or ID. He needs these to figure the windload, the moment, or breaking point. Any info is a plus. I have searched myself and come up empty, even calling our local and some out of town supply yards. Hoping someone on here can help point me in the right direction. Thanks.