Tube drawing is a metalworking

Metalworking

Metalworking is the process of working with metals to create individual parts, assemblies, or large scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts and delicate jewelry. It therefore includes a correspondingly wide range of skills,...

 process to size tube by shrinking a large diameter tube into a smaller one, by drawing

Drawing (manufacturing)

Drawing is a metalworking process which uses tensile forces to stretch metal. It is broken up into two types: sheet metal drawing and wire, bar, and tube drawing. The specific definition for sheet metal drawing is that it involves plastic deformation over a curved axis...

 the tube through a die

Die (manufacturing)

A die is a specialized tool used in manufacturing industries to cut or shape material using a press. Like molds, dies are generally customized to the item they are used to create...

. This process produces high quality tubing with precise dimensions, good surface finish, and the added strength of cold working. Because it is so versatile, tube drawing is suitable for both large and small scale production..

There are five types of tube drawing: tube sinking, mandrel drawing, stationary mandrel, moving mandrel, and floating mandrel. A mandrel is used in many of the types to prevent buckling or wrinkling in the workpiece.

Tube sinking

Tube sinking, also known as free tube drawing, reduces the diameter of the tube without a mandrel

Mandrel

A mandrel is one of the following:* an object used to shape machined work.* a tool component that grips or clamps materials to be machined.* a tool component that can be used to grip other moving tool components.- Variants :...

 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. This type of drawing operation is the most economical, especially on thick-walled tubes and tubes smaller than 12 mm (0.47244094488189 in) in diameter, but does not give the best surface finish. As the tube thickness increases the surface finish

Surface finish

Surface finish, also known as surface texture, is the characteristics of a surface. It has three components: lay, surface roughness, and waviness.-Lay:...

 quality decreases. This process is often used for the tubing on low cost lawn furniture.

Rod drawing

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 100 feet (30.5 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). This process is also use for precision manufacturing of trombone

Trombone

The trombone is a musical instrument in the brass family. Like all brass instruments, sound is produced when the player’s vibrating lips cause the air column inside the instrument to vibrate...

 handslides

Handslides

A handslide is the portion of a trombone that the player lengthens and shortens to adjust the instrument's pitch.A handslide consists of two main parts. The first is the inner slide, consisting of two tubes or "rails" which are open at both ends and are maintained parallel to each other by a brace...

 (see, for example, video of the process of making Getzen

Getzen

The Getzen Company is a family owned manufacturer and wholesaler of brass instruments. The present product portfolio consists of Trumpets, Cornets, Flugelhorns, Trombones and a Baritone Horn. Four Generations of the Getzen family have participated in the company.-Founding:In 1939, Anthony James ...

trombones.

Fixed plug drawing

Fixed plug drawing, also known as stationary mandrel drawing, uses a mandrel at the end of the die to shape the ID of the tube. This process is slow and the area reductions are limited, but it gives the best inner surface finish of any of the processes. This is the oldest tube drawing method.

Floating plug drawing

Floating plug drawing, also known as floating mandrel drawing, uses a mandrel that is not anchored whatsoever to shape the ID of the tube. The mandrel is held in by the friction forces between the mandrel and the tube. This axial force is given by friction and pressure. The greatest advantage of this is that it can be used on extremely long lengths, sometimes up to 1000 feet (304.8 m). The disadvantage is it requires a precise design otherwise it will give inadequate results. This process is often used for oil-well tubing.

Tethered plug drawing

Tethered plug drawing, also known as semi-floating mandrel drawing, is a mix between floating plug drawing and fixed plug drawing. The mandrel is allowed to float, but it still anchored via a tether. This process gives similar results to the floating plug process, except that it is designed for straight tubes. It gives a better inner surface finish than rod drawing.