SWD Inc. Fastener Sorting Corporation Specializing in Black Oxide, Passivation, Phosphating, Dip Spin Coatings, and Fastener Sorting. SWD Inc. is Chicagolands premier metal finishing, dip spin coatings and fastener sorting facility. We specialize in working with stampings and fasteners such as screws, nuts, bolts, and washers. SWD Inc. is located less than 30 minutes from Chicago, Illinois. SWD Inc. has created a tradition of exceptional production quality, complete customer satisfaction and continuing commitment to environmental conservation. SWD Inc. was the first metal finishing and fastener sorting company in the U.S. to receive ISO 14001 certification. SWD Inc. is the largest Black Oxide shop in the Continental United States. We have specialized in Black Oxide for over Twenty Five years. Other names for Black Oxide are: Black Penetrate, Black Magic, Black N, and Gun Bluing. Please contact us at (630) 543-3003 for a quote or any information regarding our plating, metal finishing, or coating systems.