Abstract: An improved key for driving tamper-proof bolts includes a plastic key handle molded onto one end of a tubular sleeve. The tubular sleeve has a transverse aperture near an end opposite the key handle, and a ball is captively held by the tubular sleeve adjacent the transverse aperture. Molded into the key handle are a chamber providing access to one end of the tubular sleeve and a channel extending transversely through the chamber. The key also includes a plastic plunger handle molded onto an end of a plunger rod axially slidable within the tubular sleeve. A camming surface is located on the end of the plunger rod opposite the plunger handle for camming the ball into the transverse aperture of the tubular sleeve. Molded into the plunger handle is a flattened surface and a flange. A pin is press-fit into the channel adjacent and parallel to the flattened surface of the plunger handle for preventing the plunger handle from rotating and for retaining the flange within the chamber of the key handle.