A seamless steel pipe is produced by piercing and rolling a solid steel billet into a hollow tube, creating a pipe without any welds. Unlike welded pipes, seamless pipes offer superior mechanical properties, uniform wall thickness, and enhanced durability. They can be manufactured as hot-rolled, cold-rolled, cold-drawn, extruded, or pushed pipes, and are available in round or special shapes such as square, oval, hexagonal, and star-shaped, with diameters ranging from 4 mm to 900 mm.