The performance of an alloy of 85% Ti 15%Mo as a filament material for subliming titanium in getter pumps is described. Using 2.1-mm-diam filaments, evaporation rates of up to 1 mg/cm/min have been achieved at filament currents of 57A. The upper limit in the evaporation rate is caused by filament failure which is attributed to crystal growth, but at values below this limit the evaporation is extremely uniform and reproducible. Comparison has been made between the performance of this alloy and a number of filaments of the type in which titanium is wrapped over a tungsten or tantalum core. The alloy was found to compare favorably in terms of peak evaporation rate and efficiency, and to be considerably better in terms of expense, reproducibility, and mechanical strength.