Our black stainless steel coating, known as CB10 or Oxi black is a super strong layer bonded to the surface of the metal. We use this coating on all of our black stainless steel fasteners including our A4 316 grade marine fasteners The surface bonding is excellent and gives a deep black colour.
CB10 is highly scratch resistant. In fact you would need to cut into the metal surface to remove the coating. Stainless steel is almost twice as hard as mild steel, so this is the perfect coating for longevity.
CB10 is also highly corrosion resistant, it does not interfere with the corrosion resistant properties of stainless steel. We have tested our CB10 black A2-70 stainless steel bolts. We have done this by leaving them outside for over 9 years in the north of England. Through 9 winters including the wettest December on record, there are still no signs of corrosion.