Period analysis of radial velocity, equivalent width, and magnetic measurements of the SB3 system HD 156324 yield identical results in all cases, indicating the system is tidally locked with orbital and rotational periods of 1.58 d. Its H alpha emission profile exhibits marked morphological departures from the usual pattern observed amongst magnetic B-type stars, which can plausibly be ascribed to tidal disruption of the gravitocentrifugal potential.