In order to improve a workpiece's shape, dimensional accuracy, and surface quality while maintaining consistent surface contact with the tool, honing is a cutting operation with bonded grain. Typically, honing is used following precision machining (e.g., grinding).
Honing is a finishing process, in which a tool called hone carries out a combined rotary and reciprocating motion while the workpiece does not perform any working motion. Most honing is done on an internal cylindrical surface, such as automobile cylindrical walls. The honing stones are held against the workpiece with controlled light pressure. The honing head is not guided externally but, instead, floats in the hole, being guided by the work surface.
Honing can achieve surface finish requirements down to 4 Ra and dimensional tolerances of plus or minus 50 millionths (.00005).
Typical honing values:
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Small Honing 0 - 0.01 mm – Machining small workpieces or thin walls. Can be found on small ground and positive turning inserts and solid carbide endmills.
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Average Honing 0.03 - 0.05 mm – A common honing size for finish and medium applications in turning and milling.
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Large Honing 0.06 - 0.08 mm – Used for heavy application or interrupted cuts.
Why Honing?
Cost effective machining method for:
- Removing stock
- Generating exacting
- Bore tolerances
- Bore polishing
- Finishing bores of almost any material such a: sprayed coatings, CGI, Ceramics, etc.
Limitations Of Honing Process:
- Honing is thought of as a slow process. However, new machines and stones have shortened hone times considerably.
- Horizontal honing may create oval holes unless the work is rotated or supported. If the workpiece is thin, even hand pressure may cause a slightly oval hole.
Application of Honing Process:
- Finishing automobile crankshafts journals
- Finishing round holes
- Finishing hollow cylindrical parts
- Finishing Engine cylinder, bearings, gun barrels, ring gauges, shafts and flange faces, piston pin, automobile crankshaft journals etc.
- Gear Hobbing
