Hard Anodising

We offer Hard Anodising to BS 5599 standards in blue or black.

Overview: Ideal for the production of hard wear-resistant surfaces on aluminium for aircraft and general engineering uses. Typical examples include cylinder bores, hydraulic & pneumatic piston surfaces, gears, pulleys, racks and cams.

Key Strengths: Key strengths of hard anodising include:

• High electrical resistance (500 - 1000V)
• Suited to HE30 grade aluminium
• High hardness rating 500HV

Limitations: There are a number of limitations associated with Sulphuric Anodising:

• Restrictions on types of aluminium suitable for hard anodising. Not suitable for free cutting aluminium. If uncertain as to suitability of your aluminium please call. It is worth calling us at the design stage
• Finished surface rougher than original, therefore higher quality surface roughness required of original than desired hard anodised finish
• Sharp edges should be radiused before processing as there is always the risk of thinning, chipping or flaking of the film under high impact load, particularly on alloys with a high zinc or magnesium content

Applications: Machinery, hydraulics and tooling.

Surface Growth: There is an increase in dimension or surface growth of between 38 and 50% of the applied film thickness which must be allowed for at the design stage.

Tanks: We offer tank sizes up to 8' x 5' x 3'.

Thickness: Standard coating thickness is up to 75µm.

Finish: Gunpowder Grey.

Selective Finishing: Masking can be undertaken to restrict the hard anodising to the waer resistant surfaces such as cylinder bores. This process usually involves the sulphuric or chromic anodising of the non critical areas with the stopping off of the areas to be hard anodised. This process is then repeated with the asking reversed.

Fast Turn Around: We offer a fast turn around because of the large size of our tanks.

Jigging: Correct jigging is essential to the resulting finish, and good jig points are required, a consideration that should be made at the design stage of a component. The use of loose, sliding or intermittent contacts will result in an unsatisfactory connection and give rise to faults such as thin coatings, burning at the contact points or even failure to obtain an anodised coating.