A forming process that reduces blank (sheet/preform) diameter through radial stretching. Unlike stretch forming, it uses a mandrel instead of a punch and spinning rollers instead of dies. As the most dominant and widely applied spinning method, bending-induced plastic deformation is its primary deformation mechanism. Compared to stretch forming, it offers greater flexibility in processing conditions, enabling production of complex rotationally symmetric shapes. Precise control of roller motion trajectories is critical, requiring deep expertise in roller movement mechanics.

Thinning spinning refers to a method that maintains the blank’s outer diameter while altering its thickness to form axisymmetric

thin-walled parts such as cones (cone thinning spinning). Key characteristics include:

-Low roller forces due to localized deformation.

-Interdependent semi-cone angle and wall thickness.

-Smooth material flow, high surface finish, and superior dimensional accuracy.

-Compatibility with materials challenging for stretch spinning.

The theoretical formula governing the process is: