In order to facilitate and reduce the time necessary for clamping together and boring a hole through at least two workpieces that are to be joined together, for example by rivets or bolts, a portable clamping and boring apparatus carries out all necessary operating steps once it is manually positioned at the intended location of the bored hole. The clamping and boring apparatus includes a tool body with a clamp device and a boring device mounted thereon. The clamp device includes a clamping yoke with a clamp jaw element at an end thereof, and a clamping cylinder that drives the clamping yoke in an axial direction toward the boring location, from an open starting position into a clamping position. The boring device includes a pneumatic boring machine adapted to receive a boring bit, and a boring feed advance drive connected to the boring machine to drive the boring bit in a feed advance direction opposed to and coaxial with the clamping direction of the clamp jaw element. The feed advance drive and the clamping cylinder are operatively coupled or interconnected so that the clamping step and boring step are automatically triggered together in proper sequence. The apparatus is especially suited for automatically clamping together two workpieces and boring holes therethrough, as necessary for forming a riveted connection between the workpieces, particularly in the construction of aircraft components.