Abstract: A tack fastener temporarily holds two or more parts together. An elongate tubular body of the tack fastener includes a longitudinal center cavity formed therein along a longitudinal center axis. A threaded hub is provided at a first end of the body and a plurality of tangs at a second end. Each of the tangs includes an enlarged tip having an inner shoulder that lies orthogonal to the longitudinal center axis. Each of the tangs has an outer surface which tapers inwardly toward the longitudinal axis in a direction toward the tip. A compression nut is mounted on the threaded hub. A stem is slidably mounted in the longitudinal center cavity. The stem includes a cone-shaped spreader with a distal end and having a contact surface with a gradually enlarging diameter in a direction toward the distal end. The spreader is movable between a position out of alignment with and a position in alignment with the enlarged tips.