Tube drawing

Tube drawing is an operation used to make a small diameter tube from a large diameter tube, by pulling the tube through a draw die.

There are five types of tube drawing: tube sinking, mandrel drawing, stationary mandrel, moving mandrel, and floating mandrel.

Tube sinking

Is the process, that reduces the diameter of the tube without a mandrel inside the die, the shape of the tube is given by the angle of the die. these type of drawing operation is the most economical, but not have a good surface finish. The parameters that have these type of process are drawing stress, emerging wall thickness, optimal die angle and, maximum possible reduction.

Mandrel drawing (Rod Drawing)

Is the process that draws the tube with a mandrel inside trough the die. This type of process. The mandrel define the inner diameter, the wall thickness and the surface finish of the inside of the tube. This type of drawing are limited by the length of the mandrel.

tationary mandrel (Fixed Plug Drawing)

This kind of mandrel drawing is that the mandrel does not move, the mandrel is fix in the frame of the draw table. The stationary mandrel is a slow process and the area reductions are limited. This kind of drawing is utilized to give a smooth finish to the inside of the tube, no other drawing is capable to give such smoothest like this.

Floating mandrel (Floating Plug Drawing)

In this type of drawing the part that gives the shape to the tube is a plug that is floating between the die and the tube. The plug then places itself at the throat of the die even when there is no mandrel to hold it there. Such a plug is called floating plug. The plug maintains it position because an axial force. This axial force is given by friction and pressure. This is one of the best type of drawing because it gives good surface finish inside and outside the tube and makes thin tubes with efficiency.

Moving mandrel (Tethered Plug Drawing)

Contrary to the stationary mandrel, the mandrel is moving. This drawing process is that a moving mandrel adheres to the drawn tube through friction and pressure and moves with it. This type of drawing give more smooth finish to the interior of the tube than the mandrel drawing.

ee also

*Pipe and tube bender

References

*http://www.metalforming-inc.com/Consulting/Tube_Making/tube_making.shtml
*http://www.thefabricator.com/TubePipeProduction/TubePipeProduction_Article.cfm?ID=1583
*http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TGJ-4CP158C-9&_user=464852&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000022310&_version=1&_urlVersion=0&_userid=464852&md5=07d91bd1c9463b184139d0ab331393e8