The Plumber's Choice steel pipes are made of the best quality steel material has a black finishing to provide greater rust resistance. Our pipes are schedule 40 and is available in various sizes to fit all your residential, commercial gas and air applications. In addition to all plumbing use these pipe nipples are also great for DIY projects to build industrial furniture industrial shelves etc. You can use these for industrial retro wall mount iron pipe shelf. Give the rustic look for indoor and outdoor applications.