Couplings slip Within the finishes of two round ducts for being joined with each other then sheet metallic screws are fastened to hold it in position. Couplings might be demanded at a particular measurement such as connections eighteen” and bigger. The shaded place while in the image down below is https://ovalconduit45677.weblogco.com/36720917/5-tips-about-round-conduit-you-can-use-today