Ancillary Services

  • Acid Etching
  • De-greasing
  • De-rusting
  • De-embrittlement
  • Assembly
  • Polishing - all metals
  • Phosphating
  • Passivation of Stainless Steel


During some of the electroplating processes hydrogen embrittlement can occur.  De-embrittlement is a heat treatment which is applied after the electroplating process to rectify and minimise the embrittlement.


Phosphate coatings are used on steel parts for corrosion resistance, lubricity, or as a foundation for subsequent coatings or painting.

It serves as a conversion coating in which a dilute solution of phosphoric acid and phosphate salts is applied via spraying or immersion, chemically reacts with the surface of the part being coated to form a layer of insoluble, crystalline phosphates.  Phosphate conversion coatings can also be used on aluminium, zinc, cadmium, silver and tin.

The main types of phosphate coatings are manganese, iron and zinc.  Manganese phosphates are used both for corrosion resistance and lubricity and are applied only by immersion.  Iron phosphates are typically used as a base for further coatings or painting and are applied by immersion or by spraying.  Zinc phosphates are used for rust proofing, a lubricant base layer, and as a paint/coating base and can also be applied by immersion or spraying.


Passivation is the process of making a material "passive" in relation to another material prior to using the materials together.

For example, prior to storing hydrogen peroxide in an aluminium container, the container can be passivated by rinsing it with a dilute solution of nitric acid and peroxide alternating with deionized water.  The nitric acid and peroxide oxidizes and dissolves any impurities on the inner surface of the container, and the deionized water rinses away the acid and oxidized impurities.  Another typical passivation process of cleaning stainless steel tanks involves cleaning with sodium hydroxide and citric acid followed by nitric acid (up to 20% at 50°C) and a complete water rinse.  This process will restore the film, remove metal particles, dirt, and welding-generated compounds (e.g. oxides).

In the context of corrosion, passivation is the spontaneous formation of a hard non-reactive surface film that inhibits further corrosion.  This layer is usually an oxide or nitride that is a few atoms thick.

ISO 9001 Logo

SMB Plating Limited

In 2005 SMB Plating Limited acquired Plym Plating Works Limited of Plymouth and the two businesses were amalgamated to form SMB Plating Limited.

The acquisition of Plym Plating Works gave added production capacity and enriched the blend of expertise and experience across the organisation.  High Quality Plating has now been going on continuously at the Plymouth works since 1972.

This heritage of quality and service does not stop the company from investigating the latest modern techniques and processes to ensure that their customers benefit from the best service at a very competitive price.