The term "rasp" is not very often used in dentistry.
It is a term that IS used in the tool and die industry to denote a tool created when sharp barbs are whittled out of the shaft of a tool, much as would happen if you were to take a knife and cut into a piece of wood without actually removing the piece...just leaving the sliver in place.
The reason we don't use that term is because it has been replaced by the word "broach", which is actually misnamed.
What is called a broach in machine shops is what we would call a "hedstrom file".
The difference is that in a machine shop, the broach would not be tapered, but would be cylindrical.
So we have a semantic problem that is not going to be solved soon because it is of so little importance.
I mention it here so that when researching the subject, the reader will know that there is a difference in terminology between the dental industry and just about everybody else.