The burnishing process is suitable both for the treatment of mass-produced components and single components, with convincing cost-effectiveness in surface finishing. The firmly adhering black iron oxide layer is resistant to solvents and alkaline solutions and when oiled offers additional protection against corrosion while maintaining its dimensional stability. The oxide layer produced has high bending strength, abrasion resistance, heat resistance and resistance to paints and solvents.

The burnished layer is produced by immersing the components in a highly alkaline solution. H+K uses the two-bath method for this process. A computer-controlled system for controlling temperature, concentration and the overall process allows us to treat single parts and serial products with maximum process reliability. 


  • Perfect surface appearance
  • Deep black surfaces
  • Layer is resistant to alkaline solutions