  Flow forming involves complicated tooling/workpiece interactions. Purely
analytical models of the tool contact area are difficult to formulate,
resulting in numerical approaches that are case-specific. Provided are the
details of an analytical model that describes the steady-state
tooling/workpiece contact area allowing for easy modification of the dominant
geometric variables. The assumptions made in formulating this analytical model
are validated with experimental results attained from physical modelling. The
analysis procedure can be extended to other rotary forming operations such as
metal spinning, shear forming, thread rolling and crankshaft fillet rolling.
