Apparatus for attaching a disk to a spindle of a spinstand includes a spindle having a fluid pressure port therethrough for delivery of fluid pressure. A spindle adapter is adapted to be attached to the spindle and for holding a disk. The spindle adapter has a piston movable therein to clamp a disk between the piston and an opposing surface in response to fluid pressure applied through the spindle fluid pressure port. A disk can be attached to the spindle by offering the disk up to the spindle adapter, and applying fluid pressure to the spindle fluid pressure port to cause the piston to clamp the disk against the opposing surface. The disk can then be spun up on the spindle.