Tube Drawing Views

General Goods

Tube drawing is a reduction process in which one end of a tube is grasped and pulled through a die that is smaller than the tube diameter. To obtain the desired size, a series of successive reductions, or passes, may be necessary. Because of its versatility, tube drawing is suited for both small and large production runs.

Tube drawing is a metalworking process to size tube by shrinking a large diameter tube into a smaller one, by drawing the tube through a die. This process produces high quality tubing with precise dimensions, good surface finish, and the added strength of cold working.[1] Because it is so versatile, tube drawing is suitable for both large and small scale production.[2].

Tube sinking, also known as free tube drawing, reduces the diameter of the tube without a mandrel inside the tube. The inner diameter (ID) is determined by the inner and outer diameter of the stock tube, the outer diameter of the final product, the length of the die landing, the amount of back tension, and the friction between the tube and the die.[3] This type of drawing operation is the most economical, especially on thick-walled tubes and tubes smaller than 12c mm (0.47r in) in diameter,[1] but does not give the best surface finish. As the tube thickness increases the surface finish quality decreases. This process is often used for the tubing on low cost lawn furniture.[4]

Rod drawing is the process that draws the tube with a mandrel inside the tube; the mandrel is drawn with the tube. The advantage to this process is that the mandrel defines the ID and the surface finish and has a quick setup time for short runs. The disadvantages are that lengths are limited by the length of the mandrel, usually no more than 100i feet (30p m), and that a second operation is required to remove the mandrel, called reeling. This type of process is usually used on heavy walled or small ID tubes. Common applications include super-high pressure tubing and hydraulic tubing (with the addition of a finishing tube sinking operation).[4] This process is also use for precision manufacturing of trombone handslides (see, for example, video of the process of making Getzen trombones.