A THIRD CLAMPING POINT for roughing, finishing and drilling operations of pieces fixed in a vertical position. Thanks to its rigid telescopic stem and its additional modular extensions, the THIRD POINT supports workpieces and opposes vibrations and flexures caused by machining operations, thus avoiding the use of expensive, heavy and bulky fastening brackets. The THIRD POINT can be fixed directly on plates or workpieces by means of standard TCEI screws or FAST MILL® coordinate modules/risers. Alternatively, it can be fixed on machine T-shaped slots. In addition to fixing, thanks to its efficient fine adjustment system, it can be adjusted for the purposes of thrust or traction to ensure verticality of workpieces before their machining.