Dear Duck:
Two round pins SUGGESTS European, 220-V, 50-Hz. Most drills use universal motors. This advice is based on these assumptions. More information would lead to better advice. (Universal motors have brushes; does yours?)
For the universal motor, 60-Hz will not hurt, just a slight reduction (possibly) in torque. Using 120 volts instead of 220 will lead to nearly 4:1 reduction in max torque, and reduction in no-load speed, but will not damage the drill. Try it. If it seems to run OK, except with low speed and torque, you could try it on 240 if you are brave.