New High-Precision Single Stroke Honing® Process Produces

New High-Precision Single Stroke Honing® process produces <2 micron cylindricity in bores up to 10X longer than diameter. Developed in Europe for cast-iron hydraulic valve bodies, process is almost 200% more precise than previously possible.

Sunnen Products Company introduces a quantum improvement in a key manufacturing process for cast-iron hydraulic valve bodies using a precision Single Stroke Honing® process that achieves cylindricity/straightness under 2 microns in bores up to 10 times longer than diameter. Developed in Europe to meet leak-free requirements for high-pressure hydraulic systems, the High-Precision Single Stroke Honing process is almost 200% more accurate than anything previously achievable for long, small-diameter, tandem bores.

Single Stroke Honing is a single-pass process that sizes and finishes a bore with a series of progressively larger superabrasive tools adjusted to a pre-set diameter. Single Stroke Honing tools rotate while passing through the bore one time and then withdrawing. The machine's servo-controlled stroking system provides flexibility with adjustable speed and various feed profiles, such as pecking, short stroke, dwell, etc. Column feed and spindle speed can be varied throughout a cycle using the machine control.

The Single Stroke Honing tool consists of a tapered arbor with an expandable diamond-plated abrasive sleeve mated to it. The external profile of the sleeve is designed for the application. Single-pass honing is ideally suited for solid bore parts with L/D (length/diameter) of 1:1 or less. Parts with much larger length to bore ratio can be honed under certain circumstances. Bores that have interruptions allow better chip flushing and reduce the load on the abrasive sleeve.  In the case of cast iron valve bodies, bore length-to-diameter ratios of 10 or greater can be single-pass honed with great success.

The High-Precision Single Stroke process utilizes a combination of proprietary tool processing, tool holding, workpiece fixturing and process parameters, without any penalty on cycle time. It is already in use by manufacturers of hydraulic valves in Turkey, Italy, Germany, Switzerland, Brazil, Sweden and the U.S.

Additional information is available from http://www.iabrasive.com/products.