Cylinder Honing

Summary

Honing provides a precise finish of a cylinder to accept a piston, while retaining a cross-hatch imperfection that allows oil to remain on the walls to promote lubrication

Basics

• The Application of the Process of Honing to Engine Cylenders, Pnuematic Cylenders, Hydraulic Cylenders, and the like
• Gives a precision finish to the cylinder bore
• Honing may be considered a self-truing grinding process - [1]. As a result of the averaging effect, the accuracy of a honed component often exceeds the accuracy of the machine tool that created it.

Other Means to Bore Finishing

• Dedicated machines and cutters can also be used (boring machines), but the boring bit can also be mounted on a mill - [2]
• Drilling - good for only 10 mil in 1" or larger drills - [3]
• Milling holes - 1 mil with a boring bar [4], from Practical Machinist - [5]

Seamless Tube, Seamed, and DOM

• DOM has a seam, so it's not seamless. It is processed over a mandrel to hide seam.
• Seamless is actually extruded - a seam is never formed
• Seamed is welded
• DOM is welded then drawn over a mandrel
• This supplier uses DOM and seamless for hydraulic cylinders - [6]

Cost

• Metals by the foot - 12" of 4.5"x0.25" tubing - $44 - [7]

Useful Links

• Wikipedia Page on Honing (in a metalworking context)]