Tube spinning is an tube metal forming technology in metal forming ,it is different with sheet metal spinning ,the blank is a tube ,the quality of tube decides whether it can be used in tube spining ,on the other hand ,tube fixture is a important tool are applied in tube spinning , improving the support strength and temperature of the tube is benifit for tube spinning .

Blank tube property

Most of tube spinning need to process 1-3mm tube ,Tube has seamless tube and welding tube .thin and big tube is welding tube, thick and little tube is seamless tube .not all the tube can be spun ,so we must need to know the different material property before we spin .

● Aluminum

Seamless tube : aluminum has 6061 or 6063 tube commonly ,other type aluminum is soft to make a seamless tube ,when the diameter is less than 100mm, you can buy standard tube from material supplier without mold cost ,if you need to make the diameter over 100mm, you need to pay additional mold cost to custom .

The hardness must be soft , it need to quenching if it is aluminum T5 or T6, otherwise it is easy to break when spin without heating .

Welding tube : you must choose the 1060 or 1070 as blank sheet ,the hardness is soft , then rolling and welding to make a tube ,the welding line will be hard if you make by other type of aluminum, the welding line easy to break in the production .on the other hand ,welding needs to use argon arc ,not laser welding ,because the argon arch welding strength is better ,argon arc welding must be made by machine instead of hand welding to make sure the welding strength is stable .

● Steel

Seamless tube : it is similar to aluminum ,steel tube type have Q235,Q275,DC04, you can ask to buy standard seamless tube or customer seamless tube from material supplier .

Welding tube : the fabrication ways is similar with aluminum .

● Stainless steel

Stainless steel grade requirement : Common stainless steel tube is SUS304 and SUS316，there is different from aluminum and steel .many people make a mistake that they buy the industrial and decorative tube to spin ,these tube can’t be spun as the hardness is higher and ductility is worse ,we need to buy SUS304 DDQ, DDQ is abbreviation of deep drawing quality ,it can used in deep drawing and metal spinning as the good ductility ,no matter the seamless tube or welding tube ,blank sheet type must be customized by DDQ.

Welding requirement : argon arch welding must be used Panasonic automatic machine to make sure the welding quality ,stainless steel tube is easier to break than aluminum and steel tube .

Tube fixture 

Sheet spinning force is offered by clamp of tailstock ,but tube need a fixture to hold the tube spinning follow the spindle ,so we need to choose right fixture to hold tube tightly ,otherwise the tube will slip relative to spindle when tube bears strong spinning force ,it is dangerous that the tube slip out .there is two fixture you can choose and buy in the market .

Air pressure fixture : It works fast and saves work time ,but the clamping force is little ,it just can be used in thin and soft tube .

Hydraulic pressure fixture : It works slow with stronger force ,it can clamp the thicker and hard metal tube .

Longer and bigger tube metal spinning 

tube diameter ＞200mm, length ＞350mm , If you spin the longer and bigger tube ,except you need to use the fixture ,you also need to design the interior spinning mold to improve the strength of the tube ,the strength of the tube is most important factor to form ,if the strength is not enough ,the tube will be wrinkled and broken in the spinning ,so spinning mold and fixtue can support the tube keep the strength .

The gap between tube and spindle mold and tailstock mold = 0.5mm

The gap is most important factor in tube spinning structure ,if the gap is less ,the support strength is not strong enough to spin .if the gap is bigger ,the tube hard to put in mold and hard to take off from mold ,it will prevent metal flow out from stailstock mold .

Thicker and harder metal tube spinning 

If the metal tube is harder and thicker ,such as thickness ＞3mm, stainless steel or titanium tube ,you need to use heating the tube and make it soft ,then it is spin quickly and easily .

Heating ways 

Aluminum : aluminum is low melting point material ,it is suitable to heat by gas heating .

stainless steel or steel : this metal tube can be heating by high frequency equipment ,it can heat the stainless steel over 800 degree centigrade quickly .