Sulphuric Acid Anodising

At Hard Anodising we specialise in delivering high-quality Sulphuric Acid Anodising services, ensuring the longevity and enhanced performance of your aluminium components. Our expertise in anodising allows us to precisely cater to both protective and aesthetic requirements across diverse industry applications.

Here’s an insight into our Sulphuric Acid Anodising services and the advantages they offer:

Understanding Sulphuric Acid Anodising

Sulphuric Acid Anodising (SAA) is commonly referred to as natural, clear, or silver anodising, representing the most prevalent form of anodising. Unlike hard anodising, Sulphuric Acid Anodising operates at a higher electrolyte temperature and lower current density. The process encompasses a broad spectrum, with sub-divisions primarily based on the application field. Notably, all SAA films are chemically sealed, barring those purposed as paint primers.

Protective Anodising


Enhanced Durability and Resistance

Sulphuric Acid Anodising significantly bolsters the anti-galling, anti-wear, and anti-corrosion properties of aluminium components. With film thicknesses typically ranging between three and thirty microns, even the thinnest films effectively negate aluminium blackening from handling. The thicker films, on the other hand, promise superior corrosion resistance and electrical insulation, without the fatigue strength loss often associated with hard anodising.

Colouration and Finishing

The oxide layer in SAA, being less dense than hard anodising, is amenable to dyeing, offering a range of colouration options. When a denser or thicker film is desirable, semi-hard anodising emerges as a viable choice, extending beyond the standard SAA offerings.

Decorative Anodising

Creating a visually appealing finish is at the core of decorative anodising. This process finds its application across various products, from promotional items to colour-coding of surgical equipment. With a natural colour of silver or light grey, the integration of azo dye colours results in bright, vibrant films. Pre-anodising treatments such as chemical brightening or dulling enable the attainment of the requisite texture, enhancing the aesthetic appeal.

Architectural Anodising

Tailored for external architectural applications, Architectural Anodising (AA) melds aesthetic finesse with corrosion resistance and mechanical performance. The aluminium oxide films generated are porous, allowing for azo dye impregnation to achieve a desired colour. A subsequent sealing in nickel fluoride ensures the pores are closed, securing the dye compounds within and delivering a durable, visually appealing finish.

Architectural Anodising holds a higher prevalence in the US and mainland Europe compared to the UK, yet its merits are universally acknowledged.

Contact Us for Premier Sulphuric Acid Anodising Services

Embark on enhancing the lifespan and appearance of your aluminium components with our distinguished Sulphuric Acid Anodising services. Our highly skilled team is geared to provide tailored solutions meeting your project requirements.

Contact us today to discuss your anodising needs and discover how we can drive value to your operations.


What is Sulphuric Acid Anodising?
Sulphuric Acid Anodising (SAA) is a process that enhances the corrosion resistance and wear properties of aluminium. By using sulphuric acid as an electrolyte in an electrically charged tank, a protective oxide layer is built up on the surface of the aluminium.
How does Sulphuric Acid Anodising differ from Hard Anodising?
While both processes aim to augment the corrosion resistance and durability of aluminium, Sulphuric Acid Anodising operates at higher electrolyte temperatures and lower current densities compared to Hard Anodising. This results in a thinner, yet durable oxide layer suitable for decorative purposes.
Is Sulphuric Acid Anodising suitable for colouring?
Absolutely. The porous nature of the oxide layer created during Sulphuric Acid Anodising is ideal for dyeing. A variety of colours can be achieved by using different dyes, making SAA a perfect choice for aesthetic applications.
Can Sulphuric Acid Anodising be applied to other metals besides aluminium?
Sulphuric Acid Anodising is primarily designed for aluminium. However, the principles of anodising can be applied to other metals such as titanium and magnesium, albeit with different process parameters and results.
How thick is the coating produced by Sulphuric Acid Anodising?
The coating thickness typically ranges between three and thirty microns depending on the application requirements. Thicker coatings offer enhanced corrosion resistance and electrical insulation.
What is the lead time for Sulphuric Acid Anodising services?
The lead time can vary based on the specifics of your project and our current workload. We recommend getting in touch with our team to discuss your requirements and obtain an accurate time estimate.
How do I get a quote for my Sulphuric Acid Anodising project?
Simply contact us via phone or email with your project details, including the quantity and dimensions of the parts you need anodised, and we’ll provide you with a tailored quote.
Is there any post-treatment required after Sulphuric Acid Anodising?
Post-treatment sealing processes such as nickel fluoride sealing are often employed to close the pores on the surface and lock in dye compounds, ensuring the longevity and appearance of the anodised layer.
For any further queries or to start your Sulphuric Acid Anodising project with us, feel free to get in touch today.

Our dedicated team is here to assist you every step of the way.

We are a dedicated provider of specialist metal finishing services, concentrating primarily on the anodising of aluminium.