Vintage bumper cleaner - Merkloos - 1950

Vintage ridge reamer

A vintage ridge reamer (in English known as a cylinder ridge reamer) is a specialized automotive tool used in the overhauling of classic internal combustion engines.
When an engine runs for thousands of kilometers, the piston rings wear the cylinder wall. Because the pistons do not reach all the way to the absolute top edge of the cylinder, a thin, raised metal edge (the 'ridge' or stootrand) forms at the top. Before you can safely lift the pistons upward out of the engine block without damaging the piston rings or the pistons themselves, this edge must be smoothed away with a ridge reamer.