What is Honing?

Honing is a final finishing operation conducted on a surface, typically of an inside cylinder, such as of an automotive engine block. This metal removal process is used after casting, sintering, drilling, boring or remaining to obtain precise bore geometry and surface finish. Abrasive stones are used to
remove minute amounts of material in order to tighten the tolerance on cylindricity.

Honing, in the last decade, has become a process better described as bore finishing because the amount of stock removal and the rates at which it can be removed have increased substantially.

To learn more about honing, click here to download a booklet
Honing Technology, Tools and Machines.

A Brief History of Honing

The idea of honing – predetermined grinding movement and universal stock removal – began centuries ago. In the 1500’s Leonardo da Vinci developed a tool for the machining of wooden tubes. The tool used a combination of rotation and stroking and incorporated an abrasive grit.

Honing tools, as we now know them, were developed at the beginning of the 20th century primarily to improve components in the internal combustion engine. The first honing tools were wooden sticks with abrasive paper. Springs forced the sticks against the cylinder walls. Soon, more complex tools were developed. In 1924, a five-bladed stick honing tool with a universal joint and spring feed was patented. In the early 1930s, honing was first used in a high production application – stack honing of connecting rods.

Below you can download educational and technical information that explain different honing techniques.

Honing Bores with Keyways and Splines(DF101)
Honing Short Bores(DF102)
Honing Blind Holes (DF103)
Obtaining Specified Finishes by Honing (DF104)
Choosing the Right Stone (DF105)
Honing Tandem Bores (DF106)
Making Manual Honing Easier with Workholders (DF107)
Fixturing Parts for Power Stroking (DF108)
Vertical Honing Fixtures (DF109)
Honing Small Bores(DF110)
External Honing (DF112)
Fixturing Design Considerations for KROSSGRINDING
Sunnen Bore Gage Article