Black Oxide Coating of Machined Parts
As a premier provider of metal finishing services, at Pentrate Metal Processing, Inc. we use our proprietary black oxide and phosphate processes on a wide variety of machined parts. We handle programs that involve finishing hundreds of thousands of small parts as well as those that consist of heavy workpieces with complex geometries and exacting dimensional tolerances.
One of our more complicated projects involved providing a black oxide finish to a workpiece which featured an abundant mix of difficult characteristics. In addition to precision splines, the oversized, 500 lb. part incorporated intricate threads and other close tolerance, multi-faceted machined features. Our challenge was to achieve full, uniform coverage of the black oxide coating, especially within the multiple cavities. We developed a racking method that allowed us to secure the workpiece and allow the bath to reach, flow through, and drain from all internal areas without trapping solution within the cavities. Our racking methods also prevent the creation of unwanted air pockets that could potentially leave bare areas on the circumference of the spline.
Another facet of our finishing capabilities is our custom designed black oxide and phosphate barrels. These barrels allow us to process parts that formerly needed to be racked. By loading the parts by hand, then fully submerging the barrels and rotating them at speeds of only one or two revolutions per minute, we achieve complete coverage while preserving part integrity. This results in a significant cost savings over rack plating. For situations that require rack plating, we have a large assortment of modular racks that accommodate most parts to avoid the expense of custom tooling.
To learn more about our finishing processes for machined parts, contact us today.