For some tubing, the weld bead is smoothed (also known as drawn), which reduces the chance of particle buildup and makes it an economical alternative to seamless tubing. With a seam on the outside and a weld bead on the inside, use this tubing when your application does not require a smooth interior.
Welded (Seams): Welded tube is produced from a strip that is roll formed and welded to produce a tube.There are two types of pipe and tube construction and each comes with their own advantages and disadvantages. Metal pipes and tubes can also be used structurally in construction, as columns and railings. Pipes and tubes are both tubular products, intended primarily for the conveying of water, fuel, gas, air, and steam.
