Experiments were performed to study the effect of erodent particle velocity, size and shape on the erosion rate os S-glass, and to investigate the erosion mechanisms associated with these variables. The S-glass specimens were subject to eroding particles of alundum and spherical glass beads. Particle sizes ranged from 60 to 400 μm; particle velocities varied from approximately 60 to 90 m s - 1 . An experimental apparatus that allows the tangential velocity component to be varied was employed. Results are presented for erosion rate vs. impact angle, and results indicate the dependence of the erosion on the shape (round or angular) of the abrasive material. Scanning electron micrographs show the effect of tangential velocity in crack propagation and material removal.