Metal spinning is a new metal forming technique in manufacturing industry .many metal products are made by metal spinning ,the mold cost is cheap and sample period is quick ,so many company choose spinning to make metal shell .There are several aspects you should consider and know before you design or check a spinning part .
①Metal sheet choice
The common metal sheet is suitable to spin includes aluminum (1060,1070,1100,3003,5052,5083,6061),brass ,copper( TU1 ,TU2),steel (SPCC,DC04) ,these metal has good ductility to spin forming, the hardness of stainless steel is harder and the ductility is worse than aluminum and steel ,the common are used in spinning includes SUS201 ,SUS304，SUS316.
Hardness :aluminum ＜copper ＜brass ＜steel ＜stainless steel
Ductility : aluminum ＞copper ＞brass ＞steel ＞stainless steel
Strength：stainless steel＞steel ＞aluminum ＞copper ＞brass
②Why do you choose metal spinning forming
If the metal shell is big or small quantity production ,you have better choose the metal spinning , metal spinning mold is cheaper and production period is shorter ,it easier to adjust the size when you need to fix the mold .
③Metal spinning capacity and advantages
Metal spinning can process diameter from 0-1800mm,height is over 1mm.thickness of stainless steel is over 5mm ,aluminum is over 10mm .all metal will has better strength after spinning ,so you can use the thinner thickness when you choose metal spinning to make the shell .
The better height of sheet spinning : stainless steel is less than 200mm ,aluminum and steel is less than 500mm
many designer don't know the thinning rate of metal spinning ,the bigger thinning rate is over 60%, you can
you also need to consider the welding ,if the thickness is less than 1mm, it is harder to weld on the metal spinning shell ,in order to make sure the welding quality ,you need the thickness is over 1.2mm.
⑤The accuracy of metal spinning shell
The accuracy of metal spinning is worse than other CNC process ,because metal spinning has internal stress make the shell ellipse .The diameter measurement is hard as the shell is soft if you caliper to check .so the assembling is different with the cnc turning parts ,it need big tolerance to fit .
Structure is another important factor to effect the accuracy ,if you design the groove ,ring or rolling the edge to improve the strength of the shell ,to reduce the internal stress effect the accuracy .the following image is the ways to improve the strength and the accuracy .
⑥Holes process ways
Most of metal spinning shell need holes to assemble ,traditional process way is hard to make the hole on it ,it belongs to thin-wall part ,it will shake when you use turning or milling to make the holes , you can use the pressing , stamping ,3D laser cutting to make the holes ,if the thickness is over 2.5mm, the shell will have good strength to make holes by turning and milling.
The metal spinning shell will be transmutative after 3D laser cutting ,because holes cutting cause the asymmetrical of the internal stress .If you want to reduce the deformation of holes cutting ,you can choose thicker sheet to spin to improve the strength ,or you use the heat treatment to reduce the internal stress .
Surface treatment of CNC spinning products
Aluminum spinning : we usually use oxidation ,powder coating ,painting spraying as the aluminum surface treatment . Oxidation and painting can't cover the spinning grain completely if it isn't polished , sandblasting and powder coating can cover the spinning lines.
Steel spinning :Electroplating and painting is used by steel material ,you should have different polishing surface according to the surface requirement .
Stainless steel spinning : Polishing is the common surface treatment of stainless steel . the spinning line is obvious because of the hardness of the stainless steel ,polishing has many technical requirement .the spinning line is thinner ,the polishing cost is lower .
⑧Welding technology of metal spinning products
Welding includes laser welding and argon arc welding ,the thickness of spinning wall decide whether the welding is easy .if the wall thickness is thick ,you can use the argon arc welding ,if the wall thickness is thin ,you can use the laser welding .argon arc welding has stronger strength than laser welding .