Tools with induction motors (as almost certainly fitted to a vacuum pump) wound normally be designed for 50 or 60 Hz use
Of course the motor will run at 5/6 the speed when run on 50Hz so the cooling will be slightly less effective and the eddy losses in the iron will be slightly higher leading to hotter running. Usually these effects can be ignored unless the motor has been very marginally designed.
An enquiry to the vendor 'might' elicit some info as to what specification is on the motor.
Brush motors tend to be marginally designed all the time and whilst the speed will not be affected , the eddy losses could become significant and the motor get hot. However, most tools with brush motors are so noisy that they are not likely to be run for long periods.
So usually you can get away with it.
The final issue is the availability of spares when buying from across the pond. Also US pipe threads are different from those used in UK
so buy any threaded fittings at the same time.
hth
Bob