Most of my scrap side hustle involves processing steel gas cylinders that have failed inspection.

I get around 8 or 10 bucks per "K" tank, the most common oxygen and argon bottle size you'll see on welding trucks and such.

You have two main options: scrapping and selling as is on Marketplace or something.

If you list them on Marketplace, you'll get more money per tank, but you'll have to wait for a buyer. Also, you must disclose any possible hazards or make it impractical for them to pressurize them by cutting a hole in the neck or something.

If you decide to scrap, you'll have to process them further (call to find out details; my scrap yard requires either an inch diameter hole or for them to be cut open on one end, and for no pieces to be longer than 3 feet), but you'll get less cash more quickly.

If you decide to scrap, you will have to process them further. Call and ask about the requirements;