Can I buy SDS drills (or à drill machine) in the USA and use it with an European bought machine (or drills)? Is the SDS "connection" the same in Europe as it is in the US?
Sorry for the language, I hope you understand
There are three different SDS sizes: SDS plus, SDS top and SDS max. You must match your tool type to the bits. Within a given tool type (SDS plus, say), the tool side is the same.
They are available in both inch and metric sizes (on the cutting end).
SDS-plus, SDS-Top and SDS-max. respectively:
The most common type I've seen is SDS-plus (incompatible with SDS-max etc). Since this system was invented by Bosch it is not a de-jure international standard of the sort overseen by a standards body. However, unlike DVD content producers, Bosch don't seem to have any incentive to make incompatible SDS products for different regions of the world. So you're probably OK if you stick to SDS-plus tools.