Pull broaching

Illustration of Pull broaching

A cutting tool is pulled axially through a hole to gradually transform it into the desired shape and tolerance

Pull Broaches are tools that have many sets of cutting edges whose cross section increase in size from the top to the bottom of the tool. The chip breakers at the top are often designed for coarser machining while at the end of the tool they are optimized to achieve the desired tolerance.
The tool is pulled through an existing hole and is gradually transformed. THERE ARE ALSO BROACHES THAT ARE instead drawn through the hole but the principle is the same.
It's usually powered by hydraulics.