A clamp for securing a tool to a multi-piece panel assembly. The clamp is especially suited for applications where access to only one side of the panel assembly is available. The clamp uses a blind temporary fastener that is secured to the panel assembly to hold the independent panels of the assembly together. The clamp includes an sleeve member that is attached to the temporary fastener and a socket that attaches to the sleeve member and is axially adjustable therewith. The clamp attaches to the temporary fastener without modification of the temporary fastener and clamps the tool to the panel assembly. The clamp is adjustable for a variety of tool thicknesses and can be removed without removal of the temporary fastener.