Expandable diameter fasteners are custom-engineered to expand in a hole to prevent fretting. These unique fasteners can eliminate the need for expensive close tolerance machining or press fits. Typical applications include: aircraft engine mounting, helicopter blade attachment, mounting of anti-friction bearings, and redesigns requiring a tighter joint. The heart of the fastener is the expandable bushing stack of alternating tapered split bushings. When a compressive force is applied to the ends of the bushing stack, the diameter of the fastener increases. When the force is relaxed, the bushings return to their original diameter, and the fastener can easily be removed and reused. The family of expandable diameter fasteners include: bolts, blind bolts, shafts, and cam-operated pins.