A disc assembly in a disc drive includes a hub rotatable about a central
axis. Pluralities of disc elements are mounted about outer periphery of
the central axis of the hub. An annular shaped disc clamp is located
about a first axial end of the hub, the annular shaped clamp holding the
outermost disc to the hub by a series of equally spaced fasteners along
an inner diameter of the disc clamp. The improvement therein consisting
of placing an offset angle on the underside, or disc-to-hub contact area.
The offset angle sloping from the inner disc contact point outward to the
end of the clamp such that application of pressure during clamping will
make a uniform contact area along the clamp surface as the clamp
fasteners are tightened to secure the clamp to the hub. This improves
flatness, axial run out, reduces repeatable run out and increases
reliability.