Microfinishing Metal Parts

In assemblies where contact to metal surfaces is critical, improvement of that metal surface becomes important. Virtually all metalworking operations including cutting, stamping, welding and forming roughen a metal surface. When that metal surface is then forced to work in critical sealing or friction zones, product performance often suffers.

Measuring Irregularities Before Electropolishing

One of the traditional instruments used to measure surface roughness is the profilometer. The profilometer, using a diamond stylus to record the irregularities of
the surface, usually gives a readout in microinches
 or micrometers. This quantifies the roughness of the surface, with a larger number indicating a rougher surface. Able Electropolishing typically reduces these microinch
 values by 50%, i.e. a 16-microinch surface before electropolishing will be improved to an 8-microinch surface afterward.

How Able Electropolishing Improves Microfinish

Illustration A depicts a typical cross-sectioned metal surface. The electropolishing process allows for a concentration of current in the peaks of a surface, thereby reducing microscopic peaks and causing a leveling action. By reducing the surface peaks, the microfinish values are reduced as well.

Illustration A

In general terms, when properly applied, electropolishing can reduce microfinish values by 50% with a removal of .0005″ from each surface. Chart B clearly shows that maximum benefit is achieved in this area, and that removing much more metal does not continue to improve surface finish.

Chart B

It is important to note that electropolishing is best suited for improving microfinish values on complex or fragile parts. Many other microfinish improvement methods such as grinding, lapping or harperizing are not suitable on multi-faceted parts or fragile stampings.

Request a Sample

To see how we can improve the microfinish on your parts, contact Able Electropolishing to schedule a free sample. We electropolish samples and return them in a few days, allowing you to see the benefit for yourself. Call us at 888-868-2900 to schedule a free sample today.