A honing machine is a machine tool used in the manufacture of precision bores to improve the geometry, surface
finish and dimensional control of the finished part. This process is called honing.
Typical applications are the finishing of cylinders for internal combustion engines, air bearing spindles
and in gear manufacturing. Types of hone are many and various but all consist of one or more abrasive
stones that are held under pressure against the surface they are working on.
The hone is usually turned in the bore while being moved in and out. Special cutting fluids are used
to give a smooth cutting action and to remove the material that has been abraded. Machines can be portable,
simple manual machines, or fully automatic with gauging depending on the application.
Modern advances in abrasives have made it possible to remove much larger amount of material than was
previously possible. This has displaced grinding in many applications where "through machining"
is possible. External hones perform the same function on shafts.