Pipe manufacturers manufacture pipes for use in industrial, commercial and residential units. A pipe is a tubular section or a hollow cylinder, used mainly to pass on substances such as liquids and gases, slurries, powders, masses of small solids. Pipes can also be used for structural applications. Pipes imply a level of rigidity and permanence. Pipe is widely used in the fabrication of handrails, guardrails, and railings; Pipe is made in many materials including ceramic, fiberglass, and metals, concrete and plastic. Typically metallic piping is made of steel or iron, such as unfinished, black (lacquer) steel, carbon steel, stainless steel, galvanized steel, brass and ductile iron.