There's a solid technical reason behind the old expression "honed to perfection" – honing really is a "perfecting" process for holes. Honing perfects the shape, size and finish of a bore, taking it to a level of accuracy other processes typically cannot match.
The principle is simple: a rigid abrasive tool, typically as long or longer than the bore itself, rotates in the bore while the part or tool are stroked back and forth. The results are stunning. Bore size can be controlled to 0.000001" (0.25µm), with finishes as fine as 2 microinches (.051 µm). Finishes can also include plateaued or relieved for engine cylinders.
In addition, honing's crosshatch surface finish retains lubricating oil or grease films. It also resists lateral drifting of parts that rotate on a shaft.
Principally, honing corrects geometry errors created by other processes. There are ten common errors caused by heat treating, welding and machining, and all are easily corrected.
- Boring marks
- Reamer chatter
- Rainbow/camber/banana shape
- Misalignment of tandem bores
And honing corrects these errors with the least possible stock removal. Most users want a uniform round shape in a bore, but honing can also impart a shape, such as a barrel or crown, in a selected region of a bore if desired.
From A to Z, honing can be used on almost any material: alinco, aluminum, carbide, ceramics, compacted graphite iron, ferrite, fiberglass, gold, graphite, Hasteloy, hypereutectic aluminum, Invar, M2 steel, Monel, Nylatron, plexiglass, porcelain, quartz, silicon, stainless steel, tantalum and zircaloy, to name a few.
Honing tools and machines are available to handle almost any shape, size or type of workpiece, from blind-bore fuel injectors and ported two-cycle engines to cannon barrels and long sections of oil-field pipe. The process easily handles tandem bores, blind bores, thin-wall parts, bores with keyways and splines, bores with lands/ports/slots, short bores, long bores, small bores, ultra-precision bores.
The various pages on our web site explain the different machine types, tooling, abrasives and lubricants. Check 'em out.