A full range of finishing processes is available either in house or from our trusted sub-contact partners.

to any Ral colour required

Predominately carried out in house.

Stress Relieving, Case Hardening, Nitriding, Through Hardening
Other sub-contract services include galvanising, precision grinding, honing and boring, deep hole drilling, EDM, Wire Erosion and Broaching.

Anodising is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts, increasing resistance to corrosion and wear, and providing better adhesion for paint primers and glues, the thicker the oxide layer, the more protection provided.  Anodising is also used to prevent galling of threaded components and anodic films are most commonly applied to protect aluminium alloys, making them scratch resistant. Anodising changes the microscopic texture of the surface and the crystal structure of the metal near the surface. Thick coatings are normally porous, so a sealing process is often required to achieve corrosion resistance. Anodic films are generally much stronger and more adherent than most types of paint and metal plating, but also more brittle. This makes them less likely to crack and peel from aging and wear, but more susceptible to cracking from thermal stress.

Generally hard coatings are required between 25 microns and 50 microns, although thicker deposits are possible. A hard anodised finish has a micron hardness of approximately 1100 HV which provides superb corrosion and temperature resistance, and excellent electrical insulation. Hard anodising is possible in various colours, but the final finish tends to be darker than natural anodising. Anodising is done primarily to protect against metal corrosion, but an anodised metal finish also has a pleasing aesthetic appearance.  The naturally anodised metal is silver or light grey, depending on the aluminium alloy and its surface finish.  A wide variety of other colours can be achieved using dyes.  The brightness of the finish achieved is largely due to the purity of the aluminium, but it can be enhanced by chemical, mechanical or electro-chemical methods.
  • 1000 Series-Say 1080A, 1200A, 1050 - ideal for anodising
  • 2000 Series-Say 2014A, 2024 - a satisfactory anodised layer can be produced
  • 3000 Series-Say 3103, 3105 - ideal for anodising
  • 4000 Series-Say 4043A,4047A - a satisfactory anodised layer can be produced
  • 5000 Series-Say 5005, 5056, 5083, 5251, 5454 - ideal for anodising
  • 6000 Series-Say 6061, 6063, 6082, 6262, 6463 - ideal for anodising
  • 7000 Series-Say 7020, 7075 - ideal for anodising

Iridite NCP (non-chrome chemical process) is a process that offers extremely high resistance to corrosion and the ability to withstand high temperatures. It is environmentally compliant as it contains no hexavalent or trivalent chromium compounds.It adds a protective chromate conversion film coating on aluminium and its alloys. Iridite is often used for high or low frequency electrical applications, as Iridite coating has a minimal effect on aluminium’s electrical characteristics when used at lower concentrations. In addition, it is often used as a protective coating for abraded anodized surfaces and to provide an electrical contact. Iridite coating can be applied using dip, brush, swab, or spray methods and creates coatings in shades ranging from clear to dark yellow.  The darker shade of coating, the greater the corrosion protection.  Yellow Iridite coating can be left as the final finish or can be dyed other colours.

Once coated with Iridite there are a number of further finishing options:

Iridite coating can act as a base key for paint application and high performance top coats and lacquers.
Iridite provides an excellent base for rubber bonding.
Once Iridite coated, the aluminium surface can be welded either by shielded arc method or by spot welding.

Electroless nickel plating is an auto-catalytic chemical deposition of a nickel coating normally alloyed with phosphorus on a substrate. Unlike electroplating, it is not necessary to pass an electric current through the solution to form a deposit. This plating technique provides excellent wear and corrosion resistance, hardness and lubricity. Electroless nickel plating has several advantages versus electroplating, free from flux-density and power supply issues, it provides an even coating regardless of work piece geometry. The process can plate recesses and blind holes with stable thickness. Matt, semi-bright or bright finishes can be obtained. It is suitable for a wide range of metals including titanium, aluminium, alloy steels, stainless steels, beryllium, magnesium, copper and its alloys, nickel and its alloys.  Given the right pre-plate catalyst, E.N. can even deposit on non-conductive surfaces. E.N. is harder as deposited than electrolytic nickel. This extra high level of hardness reduces corrosion resistance. Types of electroless nickel plating Medium Phosphorous (7.5–10% phosphorous content): ENPLATE NI436 process chemically deposits a uniform nickel phosphorous alloy and is capable of plating on a wide variety of substrates including stainless steel, carbon and alloy steels, copper alloys and aluminium alloys. The ENPLATE NI436 is recommended where superior corrosion resistance is desired. Uses include various components in the electronics industry, oil and gas, printing, aerospace, and the chemical processing industries. ENPLATE NI436 is particularly useful for food and meat processing applications, as well as for medical and surgical parts due to its resistance to staining. High Phosphorous (10-12% phosphorous content): ENPLATE Ni 425E/ENfinity Energy* ENPLATE-Ni-425EA high phosphorous Electroless nickel process designed for corrosion protection and high build up applications. It is an advanced process designed to produce deposits exhibiting superior performance in many engineering and functional applications. The ENPLATE Ni 425E process chemically deposits a uniform nickel phosphorous alloy and is capable of plating on a wide variety of substances including aluminium alloys, stainless steel, carbon and alloy steels and copper alloys. The ENPLATE Ni 425E is recommended where superior corrosion resistance is desired. Its uses include various components in the electronics industry, oil and gas, printing, aerospace, and the chemical processing industries. ENPLATE Ni 425Eis particularly useful for food and meat processing applications, as well as for medical and surgical parts due to its resistance to staining. The high phosphorous content of the deposit adds to its functional properties including a compressive stress with resulting minimal fatigue debit. The narrow melting range of the deposit makes it suitable for certain welding and brazing applications.
Copper is an excellent conductor and copper plating can be used for EMI (Electro Magnetic Interference) and RFI (Radio Frequency Interference) shielding purposes. The deposit from copper plating is very bright and has excellent levelling properties also copper plate naturally kills bacteria, so it is frequently used to plate laboratory and medical equipment. Copper's excellent thermal and conductive properties make it a useful substance in numerous heating, industrial and electrical applications. Copper coatings are also commonly used in corrosion protection.
Silver Plating is used where silver is specified for its conductive properties. Bright or satin finishes are available and can be applied to many different base metals.
Tin plating is very cost-effective, as tin is a readily available resource and therefore much less expensive than more expensive metals such as platinum, gold or palladium. Tin is a silvery malleable metal that is used to coat other metals to prevent corrosion. The electrical and electronics industry are heavily dependent on tin and tin alloy coatings for solderability most of which is done by electroplating. Tin plated metal is also used for food packaging giving the name to tin cans which are made mostly of steel. Tin is one of the easiest metals to electrodeposit and one of the advantages of electroplating is that no limitation is imposed on the thickness of tin that can be applied.  Tin is usually plated with a bright or matt finish. 
Matt tin coatings are made in electrolytes without the addition of brighteners. Matt tin has a dull appearance, but the level of internal stresses in matt tin depositions is much lower than it is in bright tin depositions. Dull tin is ideal for electronic or precision components. Deposits give good solder ability even after heat or steam ageing. Tin plating is widely used in the following industries:
  • Electronic components manufacture 
It has conductive properties and protects the base metal from oxidation, so preserving solderability
  • Telecommunications
  • Food processing 
It is non-toxic, ductile and corrosion resistant Aerospace
The corrosive effects of rust on any metal component can be costly and dangerous. Zinc plating is frequently used to protect metals such as iron and steel against of corrosion. Zinc plating involves the electro deposition of a thin coating of zinc metal onto the surface of another metal substrate. The zinc coating creates a physical barrier that prevents rust from reaching the underlying metal surface. Zinc is chosen because of its ability to fight corrosion. In addition to forming a physical barrier, the zinc serves as a sacrificial coating; the zinc coating will corrode instead of the metal substrate that it protects. Zinc reacts with atmospheric oxygen to form zinc oxide, zinc oxide reacts with water to form zinc hydroxide, which bonds with carbon dioxide to produce a thin layer of zinc carbonate. The zinc carbonate adheres to the zinc on the coated metal to provide even more corrosion protection.
Zinc nickel plating achieves exceptional corrosion protection with high temperature resistance that meets the demands of many industries, even after heat treating (Thermal shock). The alloy gives exceptional sacrificial corrosion resistance and can be readily passivated with additional top coat sealers. Zinc Plating’s excellent corrosion resistance and cost-effectiveness make it the popular finish for the majority of hardware parts, which tend to be zinc, rather than cadmium plated. Zinc plating passivation gives a choice of clear, gold, black and olive passivates as a final finish, or it can form a good base for future painting or powder coating.

Zinc Phosphate is used for rust prevention on ferrous metal and is a lighter alternative to manganese phosphate while providing resistance to harsh elements that tend to wear products quickly. Dark grey in colour zinc phosphate is suitable for paint pre-treatment.
Manganese phosphate is used to pre-treat ferrous metal prior to painting and to increase corrosion resistance. The coating, dark grey in colour creates a heavy crystalline finish on ferrous surfaces and absorbs oil and other lubricants. 

Gold plating is often used in electronics to provide a corrosion-resistant electrically conductive layer on copper, typically in electrical connectors and printed circuit boards. Gold coatings are used in engineering applications for the corrosion and tarnish resistance, solderability, wear resistance, bond ability, low and stable electrical contact resistance and infra-red reflectivity. It does not form an oxide film on its surface and has a low contact resistance, the finish can be either bright or dull.
Used by some of largest oil and marine companies due to the excellent corrosion resistance. The components are plated using a High Phosphorous Electroless Nickel Plating Solution with a deposit thicknesses ranging from 25–150 microns which is then heat treated at 605–610 degrees centigrade causing the Nickel structure to change and is diffused into the base material of the components.

Hard chrome plating, sometimes referred to as functional chrome plating, can be applied in thick layers for heavy industrial applications. It increases wear and corrosion resistance whilst creating a low co-efficient of friction. With abrasion being the most common and destructive wear process found in industry, hard chrome has the potential to solve many problems in pumps, valves, bearings, etc.

Also known as ‘alodining’ or ‘chromating’, alochroming is a chemical process that adds a corrosion-resistant protective coating to aluminium and its alloys, and acts as a primer for painted aluminium. Although pure aluminium oxidises with air to create its own protective coating, untreated aluminium alloys have little protection against corrosion.
When used in conjunction with anodising, alochroming creates a protective coating on aluminium that doubles its resistance to salt water, compared to anodising alone.  Alochromed parts become hydrophobic with age, providing a very high level of long term protection against water or other moisture.
The main benefits of Alochrom coating for aluminium are:

  • Parts retain the majority of their original electrical conductivity
    Adds no extra weight
  • Pre-process dimensions remain unaltered
  • Corrosion resistance
  • Moisture resistance
  • A primer key for paint
  • Low electrical resistance
  • Scratch repellent surface
  • Marks like fingerprints just wipe away

Alochrom 1000 adds a transparent coating whilst Alochrom 1200 adds a gold iridescent coating.

Also known as electrochemical polishing, anodic polishing, or electrolytic polishing, electropolishing is an electrochemical process that removes unwanted materials from metallic components. Its purpose is to polish, passivate, and deburr metal parts. Electropolished metal is metallically pure, stress free, bright, decorative, chemically passive, smooth and free from minor burrs. A superior surface finish is achieved by electromechanically removing a layer of metal under controlled conditions. The final finish is free from inclusions, very smooth, and offers an unrivalled level of corrosion resistance. Because the process of electro polishing provides a reduced coefficient of friction, it dramatically improves metal’s resistance to corrosion in harsh environments.  The smooth, blemish free surface is resistant to bacteria and provides excellent light reflectivity. Hardness

These are both acid chemical treatments for stainless steel, developed to remove contaminants, discolouration and scaling. The two processes combined together result in a clean, chemically passive and corrosion resistant oxide surface film on stainless steel. Stainless steels need to be pickled before they can be passivated, as the surface needs to be clean, free from contamination, and free from any scale resulting from previous welding operations.

Although two treatments are often performed together, they are not the same:

  • Pickling is done first and removes scale via the application of strong acids. It usually involves nitric/hydrofluoric acid mixtures
  • Passivation adds a passive outer coating to the metal via an oxidation process using nitric acid. Sometimes Nitric acid alone can also be used to remove any light surface iron contamination after which the acid facilitates the passivation of the cleaned steel surface.

All of the above is an overview of finishes and treatments available either in house or from our mainstream sub-contractors, this is not an exhaustive list so please do get in touch to discuss any other requirements you may have.