Seamless elbows, also known as seamless steel pipe elbows or seamless pipe elbows, are categorized into two types based on their manufacturing process: hot-rolled (extruded) seamless elbows and cold-drawn (rolled) seamless elbows. The cold-drawn (rolled) pipes are further divided into round pipes and shaped pipes.

The raw material for rolling seamless elbow pipe fittings is round billets, which are cut into blanks of approximately one meter in length by a cutting machine and then conveyed to the furnace for heating. The steel billets are heated in the furnace at a temperature of about 1200 degrees Celsius. The fuel used is hydrogen or acetylene. Controlling the furnace temperature is a critical issue. After the round billets are removed from the furnace, they are pierced using a pressure piercing machine. The most commonly used piercing machine is the conical roller piercing machine, which is highly efficient, produces high-quality products, allows for large piercing and expansion, and can pierce various pipe fittings. After piercing, the round billets are sequentially subjected to three-roller oblique rolling, continuous rolling, or extrusion. After extrusion, the pipe is removed and sized. The sizing machine forms the pipe fittings by rotating a conical drill at high speed into the steel billet to create holes.