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We provide a fast, high-quality anodising service that you can rely on. Customers from all over the UK and beyond choose us for our attention to detail and superior standards. Our quality system is designed to spot issues before they happen and save you time and money. We have an on-site laboratory for continual monitoring of tank chemicals, we do a full visual inspection of parts before and after processing, and we check thickness using eddy current gauges.

Choose a service that gets it right first time with fast turnaround and friendly service to match - get in touch with us today.

What is anodising?

Anodising is type of metal finishing process that produces a translucent oxide coating. This oxide compound becomes integral to the metal and won't flake off. Commonly used for plating aluminium and its alloys, it can also be applied to other non-ferrous metals such as titanium, zinc, magnesium, copper alloys, stainless steel etc. The oxide layer is typically 5-30 microns thick. Anodising was originally developed at the turn of last century with one of the first patents granted in the USA to Mershon in 1913 for cookware. It was first used on an industrial scale in Britain to prevent the corrosion of aircraft parts.

Where is anodised aluminium used today?

From satellites hurtling through space to the smallest items in our homes, anodised aluminium components are used in thousands of industrial, commercial, and consumer applications including:

  • Architectural categories and structures of all types.
  • Appliances such as microwaves, refrigerators, and other household items.
  • Commercial and residential construction and building products.
  • Food equipment.
  • Motor vehicles, boats, aircraft, and aerospace components.
  • Furniture.
  • Industrial and home electronics such as TVs, smartphones, and computers.
  • Sporting goods.

What are the benefits of anodising?

Anodising is chosen to finish surfaces for a number of important reasons:

  • The coating is much thinner than alternatives such as powders and paints.
  • Strong, durable, and incredibly hard – second only to diamonds in hardness.
  • Abrasion and corrosion resistant.
  • Lasts for a long time – pretty much forever.
  • Surfaces will not peel, chip, or flake.
  • Safe, non-toxic, and chemically stable.
  • Increases fire protection from 600°C to 2000°C.
  • Environmentally friendly – components can be recycled easily.
  • Cheaper than painting or powder coating.
  • Produces a brighter, more beautiful looking finish – either clear or long-lasting colour.

Types of anodising

Hard anodising

This is mainly a functional coating used for the highest increase in hardness, anti-wear, anti-corrosion, and electrical resistance. Thicknesses range from 25-80 microns depending on the substrate. Often used for military, aerospace, and marine applications. The process is carried out in a solution with a high concentration of sulphuric acid than usual, at a lower temperature but higher voltage.

Sulphuric acid anodising

This process is the most popular type of anodising and is often used for decorative purposes. Film thickness range from 5-25 microns with dye colouring requiring 10-15 microns. Titanium can be coated at significantly lower thicknesses.

Chromic acid anodising

This process is useful for applications such as castings or where fatigue strength must be maintained. Films are relatively thin at between 1-10 microns. This makes it unsuitable if colouring is required.

Phosphoric acid anodising

This is used as a pre-treatment for structural adhesive bonding within the aerospace industry. The film thickness is 0.1-5 microns and is extremely durable under adverse and high-humidity conditions. This is a functional and priming finish rather than a decorative one.

Colour anodising

To achieve a colour finish, a dye is usually used. The pores in the coating absorb the dye and a sealant is applied to lock in the colour. The vividness of the colour will depend on the thickness of the coating. Light colours can be achieved with thin coatings but deep colours usually require a greater thickness.

Our standard dye colour range includes black, gold, blue, and red. We can seal with hot water, dichromate, nickel acetate, nickel fluoride, and PTFE.

How long does the anodising process take?

The anodising process is relatively short and usually only takes a few hours. The standard stages are:

  1. Cleaning
  2. Pre-treatment
  3. Anodising
  4. Colouring (if required)
  5. Sealing

Most work can be scheduled, jigged, processed, packed, and delivered within days depending on the amount of work on site. However, items with complicated jigging requirements or that need multi-step processes and masking, can have much longer lead times.

What affects the quality of the anodising?

The grade and condition of the aluminium can have a significant effect on the final product. The colour of the clear anodised film and shade of a dyed coating are influenced by the:

  • composition of the aluminium, different alloying agents in the base material.
  • colour of the anodised film.
  • film thickness.
  • surface finish and texture from different machining methods.

Anodising grows at right angles to the surface and where this growth meets at external sharp corners the coating can spall. Thicker hard anodised surfaces are susceptible to this spalling so corners should be radiused as much as possible.

Electroplating vs Anodising

Plating uses electricity to reduce a metal salt from a solution and deposit it onto a metal surface. Anodising is a different process – it causes certain metals to oxidise in a controlled way to form a film which adheres to the underlying substrate. The two processes look similar in the way they are carried out but they are very different in chemical and metallurgical terms.

How our anodising service can help you

We provide anodising services for the most challenging components and applications. We often take on the projects that other anodisers are unwilling to do. Our extensive experience in dual-finishing, masking, and multi-process finishing means we can often solve otherwise unsolvable problems. Get in touch with us for your next tricky project.

Anodising standards

We can anodise to the standards shown below. We also hold a large library of customer-specific, superseded and legacy specifications so contact us if you need any help.

Sulphuric anodising

  • BS 7599 (BS 12373-1, BS 1615)
  • BS EN 2284
  • AMS 03-25 (Def Stan 03-25)
  • MIL-A-8625

Hard anodising

  • BS 10074 (BS 5599, Def Stan 03-26)
  • BS EN 2536
  • MIL-A-8625

Titanium anodising

  • BS M 58 ISO 8080

For more information download our anodising info sheet or contact us for advice or a quote.