The frictional sliding of simulated faults containing crushed Westerly granite was studied in a series of constant stepped velocity experiments. Confining pressures were varied from 0.00733 to 7.33 μm/s. The strain rate sensitivity B, that is, the slope of the frictional stress change Δμ with the logarithm of the change in velocity, (log10(V2/V1)), was found to be low and pressure dependent, increasing with increased confining pressure to a maximum of approximately 0.01 at 300 MPa confining pressure.