What’s Isotropic Superfinish ISF Metal Finishing and Why Would I Want It?
Examining a metal through a microscope will lead you to notice the peaks and valleys in it – the result of manufacturing and the tooling process. Elementary science tells you that gears that interact with each other (example, metal to metal) will produce fiction, and ultimately heat. In a race car application, you want to have the smoothest surface possible for metal to metal contact to lessen the friction and heat which will allow you to effectively use more of your horsepower and make your parts last longer through reduced temperature.
ISF is considered as the Super Bowl of metal finishing. Grinding is the conventional final metal finishing operation performed on engineered metal-to-metal contact surfaces such as roller bearings and some gears. It results in a surface with a unidirectional pattern that corresponds to the direction of the final grinding operation. Using successively finer grinding wheels is okay but it may prove to be expensive, ineffective and repetitious. The products of such a process is just a surface that has closer-spaced rows and shorter height asperities.
The areas of aerospace, automotive, medicine, military, motor sports and power generation have widely used this procedure. Will this damage my part or reduce its size? The “cutting” process takes a minimal amount of material from your part, but leaves you with a part that’s “isotropic”, or uniform in all directions.
The Federal Aviation Administration (FAA) has approved the use of this metal finishing process – this may explain why such is utilized in many industries and in a lot of military applications. How does this operate then?
The ISF Process is a chemical and physical procedure that knocks the peaks down flat by cutting and taking a very, very minute (3/10000 of an inch) amount of material from your part. This process should be differentiated from grinding or buffing which “folds over” the peaks and actually makes a worse finish. Once the peaks have been cut down, you’re left with a flat consistent piece of metal that will operate more efficiently as it interacts with other metals.
Ideally, we do parts like transmission gears and ring and pinion gears to minimize drag and more effectively use the horsepower you already have. The metal finishing process is a 2-stage process that finishes with a “burnish” that makes the part come out appearing shiny, almost as if it’s chromed.
