Finishing and Processing

Home / Production / Finishing and Processing

Visaf performs further processes on screws, bolts and nuts, such as heat and galvanizing treatments, based on the customer’s requirements. These additional procedures give the finished product greater resistance and a different look.

Heat treatment

Visaf makes use of qualified and selected suppliers to perform hardening or carbonitriding treatments with or without tempering on its products. Tempering is a metallurgic process consisting of immersing steel pieces, heated at high temperatures (ranging from 721°C to 910°C), in a liquid or gaseous mixture that can separate carbon and nitrogen (UNI 5479-70). This process is performed at a temperature of about 775°C. The metals immersed in the mixture for about 3/4 hours generate a 0.10/0.15 mm deep cemented layer. The thickness obtained varies from 0.05mm to 0.55mm. Carbonitriding, which is performed by using low carbon steel pieces, produces screws with resistance class up to 8.8.

Galvanizing treatment

Visaf also sells unprocessed products, although most customers prefer our company to deal with galvanization. Thanks to specialized suppliers, we can ensure all the main galvanizing processes, including nickel-plating, zinc-nickel-plating, brass plating, white zinc plating, high-resistance white zinc plating, black zinc plating and silver plating. At the end of the production cycle, Visaf monitors products by means of specific quality and thickness control equipment.