Merchant couplings are machined from rolled steel, making them the only fittings we offer that are crafted from the same industrial steel as our pipes. Manufactured to the same specifications as our other fittings, they provide the added strength and durability of steel. Hydrostatically tested, these couplings are ideal for decor as well as plumbing applications in air, gas, and liquid propane. Each coupling connects two pipes of the same diameter for a strong and sturdy extension. You will recognize PIPE DECOR parts and accessories the moment you hold them—beauty and beast, strength and style. These are real industrial fittings for your decorations and designs. Accept no substitutes. Extra pieces and accessories are available for custom projects and expansions. Plug and play as desired. Perfect for any DIY project, these fittings complement a variety of looks and aesthetics, including steampunk lighting, industrial, factory, French country farmhouse, vintage, retro, reclamation, DIY customized, modern, and more. We recommend cleaning and sealing each fitting before use. IPS threads provide compatibility with other project materials such as lamp parts, valves, and more, and work with any pipes, fittings, and PIPE DECOR furniture kits of the same diameter.