The hand tool is held under the operators arm and by using
leverage off a peg in a T-rest, the material is worked in an arc motion
from the bottom to the top. This motion is repeated until the blank has been
drawn down to follow the same contour as the mandrel.
Roller metal spinning has the same basic concept as metal spinning by hand but rather than a tool under the arm, a roller mounted on a hockey stick (scissor like tool) is used.