Deep drawing die engineer tell you what’s the thinning drawing?
Thinning drawing is a normal processing in the drawing process. It’s generally used to make the work piece with uneven wall and bottom thickness and the high height ,such as high pressure vessels, autoclaves, etc., or for multi layer capacitors thin-walled tubular blanks.
the characteristics of thinning drawing
1.The gap between the punch is smaller than the blank thickness,and the straight wall of the blank part received the pressure when go through the gap, resulting in significant thinning phenomenon, leaving the height of the sidewall, so we called thinning drawing..
2.The quality of thinning parts is very high, the wall thickness is relatively average, wall thickness deviation within ± 0.01mm, surface roughness Ra value below 0.2um. And due to two-way pressure, the grain is fine, improve the strength.
3.No wrinkling problem (compared to non-thinning),blanking device is not required.
4.The residual stress of the Thinning parts is large,some are even break during storage,this phenomenon can be eliminated by the use of low temperature tempering
two ways of thinning drawing
1.wall thickness thinning, inner diameter will not reduce significantly—— this method is commonly used.
2.wall thickness and inner diameter botha are reduced ——- deformation and stress is more complex, the workpiece is easy to break,so usually not applied.
The common material in the thinning drawing are as below: copper, oxygen-free copper, phosphor bronze, aluminum, aluminum alloy, low carbon steel, stainless steel and so on.
Hope above brief description of thinning drawing will be helpful for you !