Torque measurements, which can be related to viscous dissipation, were made in a simulated disk drive consisting of a single or multiple corotating disk stack enclosed in an axisymmetric shroud. The effects of rotational velocity, axial and radial spacing, and the position and thickness of simulated read/write arms between disks on torque were studied. Correlations are presented to describe the results of the unobstructed cases and the cases with the read/write arms at their innermost position, and a method is introduced to calculate the torque at intermediate arm positions.