Abrasive Flow Machining (AFM) was developed by Extrude Hone Corporation in 1966, AFM is a very precise and economical method of smoothing and polishing internal surfaces and producing controlled radii. The process is particularly useful for difficult to reach internal passages, bends, cavities, and edges. The AFM process uses a specially formulated abrasive laden polymer, hydraulically forced over, or through, areas requiring finishing.