A stable TiCl4 plasma was produced using a simplified d.c. torch. The arc was struck between two concentric ring electrodes, 4 min apart, and rotated using a magnetic coil. The electrode material was a new TaC composite. The arc was operated at 100 A for up to 1 h using plasma gas containing 0-30% TiCl4. The voltage was 24-60 V, depending on the TiCl4 concentration. The electrode erosion rate was of the order of 20 mug/C. It is shown that the erosion rate is a function of the aerodynamic drag of the arc column.