With the new burnishing agent Nigrit VA-Extra, the german specialist for metal chemistry is further expanding its portfolio. The new product is intended for cold burnishing and blackening for special steel, alloys and high-alloy stainless steels.

In order to create a black colouration on metallic surfaces, Emil Otto GmbH offers a range of different burnishing agents. For aluminium and aluminium alloys, iron and steel, copper, brass, bronze as well as titanium and titanium alloys, Emil Otto already offers burnishing agents of the Nigrit series. With the newly developed Nigrit VA-Extra, special alloys can now also be processed. By soaking the workpieces in the solution, black mixed oxide layers are formed which protect the surface. The layers created by burnishing are resistant to bending and abrasion, which makes subsequent processing of the metal possible.

“Depending on the material, blackening occurs relatively quickly, approx. 15-30 seconds after application.  If the workpiece remains in the Nigrit VA-Extra longer, loose oxides accumulate on the surface, which have to be removed after the process,” Markus Geßner, Marketing and Sales Manager at Emil Otto GmbH, explains the use of the new Nigrit solution. After removing the loose oxides, which can be done with the product Neutrasol developed by Emil Otto, the workpiece must be dried and preserved. Emil Otto also offers a suitable product for preservation. The after-treatment fluid is a temporarily effective, preserving metal protection that can be applied thinly after the Nigrit VA-Extra has been used. All burnishing solutions are intended for immediate use in metal processing.