Metal Surface Treatments

Surface treatments for steel, stainless steel, aluminum and other metals

If you want to have the surface of metal objects galvanically, chemically or mechanically processed, Multinal is the right place. Whether it is hundreds, thousands or a few copies that need to be surface-treated. Multinal combines the old trusted craftsmanship with modern techniques, resulting in top quality and an excellent decorative, protective or anti-corrosion layer. In addition to the wide choice of various surface treatments, Multinal also offers pre- and post-processing, packaging, assembly and transport.


Advantages of surface treatment
  • Added value for your product
  • Corrosion protection
  • A sleek appearance
  • Beautification or technical coating
  • Qualitative coating
For metal products and machine parts

Powder coating

If you want an excellent corrosion protection for your product, but also want a long life and less maintenance, Multinal Group offers plenty of options with its powder coat treatments.

Whether it concerns powder coating of a few pieces or a series of thousands of copies: we don’t mind.

With over 55 years of experience, we know what it takes to effectively apply a powder coat layer for optimal results. Powder coating or coating not only provides good protection against corrosion, but also ensures a long service life, less maintenance and also gives your product a beautiful and sleek appearance. It is also possible to powder coat your product in any desired color.


Advantages of powder coating
  • Coating is an excellent protective layer against corrosion
  • Long service life for your metal product
  • Less maintenance due to coating
  • Sleek, smooth appearance
  • Applicable for both indoor and outdoor applications
  • Can be applied in several powder coat layers
Powder coating: many possibilities

We do not care if you want to powder coat single pieces or bulky and heavy structures, we are happy to arrange it for you. We have the right powder coating options for both indoor and outdoor applications. For example, we can apply a single-layer, two-layer or three-layer powder coating in which we work with three types of powder coating treatments. For indoor applications with epoxy or epoxy / polyester or outdoor applications with special polyester.

Colors and effects

With our many powders, we offer colorful options, even if your color is special. RAL and design colors, transparent coatings or special structure effects are carefully executed by our professionals.

But also hammer blow, ripple or metallic effects and the desired degree of gloss are linked with craftsmanship to the most modern techniques.

Remove rust and optimal adhesion

Our people understand their profession and know what is involved in powder coating. This combined with the commitment and dedication of people who do everything to achieve top quality of the coating and fast delivery times. It goes without saying that we have the expertise in-house to radiate carefully as a pre-treatment for coating. With blasting we remove rust from mill scale, glow skin and welds, which also promotes optimal adhesion of the powder coating.

For stainless steel, carbon steel and aluminum products

Pickling and passivation

Multinal Group has the right expertise to effectively pickle and passivate stainless steel such as sheet metal, tubes, piping, piping, mounting parts, grids, frames, pipes, heat exchangers, flanges and housings.

With multiple pickling plants in the Netherlands, we know better than anyone what is involved in the professional treatment of your product. In addition to the shape, size and best applicable technology, we naturally monitor our pickling procedures with regard to the environment, safety and acid residual treatment. This way you can be sure that the corrosion resistance, and thus the durability of your product, is increased.


Options for pickling and passivation
  • Pickling and passivation of stainless steel, aluminum and carbon steel according to ASTM A380 standard;
  • Support and drawing up a specific pickling procedure for your customer;
  • Pickling treatment is also possible according to the standard of your customer;
  • Pickling in immersion baths or spray pickling in our pickling plants
  • Pickling at your location in the Netherlands or at an international location.
Why pickling and passivating stainless steel?

A chromium oxide layer is naturally formed on the surface of the stainless steel, which gives the material its protection.

This chrome oxide layer is damaged by various mechanical operations such as: sawing, cutting, setting, milling and welding.

Due to these operations, there is a risk of “iron inclusion” occurring. As a result, stainless steel can eventually rust.

About the treatment

By pickling processed stainless steel in a solution of, for example, nitric acid with hydrogen fluoride, carbides, iron particles, but also annealing, rolling, forging and casting skin are removed from / from the surface. After the pickling treatment, the parts are rinsed well and the chromium oxide layer (the passivation) can again form naturally.

This natural passivation can take 24 – 48 hours to form. Some specifications or customer requirements require an additional passivation operation. This passivation layer is formed after 30 minutes by immersing the parts in, for example, a nitric acid solution and rinsing them well again.

On location or at one of our locations

But you can also come to us for effective (spray or brush) pickling and passivation of stainless steel piping systems, installations, production units, machines, boilers, heat exchangers, cooling towers, tanks and other production parts.

With years of experience with stainless steel pickling and passivation on location and with several pickling plants in the Netherlands, we have the options for you, so the choice is yours.

For stainless steel


Electrolytic polishing of stainless steel

You have come to the right place at Multinal Group for electrolytic polishing of stainless steel. Whether it is a functional application or a decorative for the stainless steel, our professionals know what it takes to make the best possible use of the properties of electrolytic polishing in combination with your stainless steel product. We provide serial productions, but also single or specialist stainless steel pieces. Electrolytic polishing includes stainless steel boilers, pumps, wire baskets, filter baskets, semiconductors, stainless steel medical instruments, funnels or hoppers, sorting sieves and stainless steel parts for machines.

Electrolytic polishing process and stainless steel

As the name suggests, the electrolytic polishing process has a limited “depth effect”. For electrolytic polishing, relatively much power is required relative to, for example, galvanizing. In order to be able to do the machining properly, matching the contact points with the material is very important. If there is a desire to electrolytically polish deeper surfaces, a special auxiliary cathode is used, so that, for example, the inside of a funnel can also be treated.

Multinal Group has a wide range of metal surface treatments, of which the electrolytic polishing of stainless steel is often used in combination with the (pre) treatment degreasing and pickling and passivation. Are you unsure whether electrolytic polishing best suits your requirements and / or wishes? Then do not hesitate to contact us.

Shine and electrolytic polishing of stainless steel

With electrolytic polishing you can give the surface more shine. This surface treatment enhances the appearance or appearance of the material. Scratches or other imperfections are more visible with electrolytic polishing in the glossy surface. Stainless steel electrolytic polishing cannot be compared to mechanical polishing. During mechanical polishing, for example, scratches are also removed by the “smearing effect”.

Surface cleaning and stainless steel electrolytic polishing

In the electrolytic polishing of stainless steel, depending on the current setting and treatment time, a few to a few tens of µm of material is “removed” from the surface, simultaneously removing the impurities. In addition, the iron is partly removed from the surface, which creates a “nobler” surface.

Smoother surface and stainless steel

With the electrolytic polishing treatment, a stainless steel surface becomes smoother. The advantage of this is that the surface is easier to clean, less attracts “dirt” and therefore stays clean longer. This is, for example, a reason why many stainless steel parts in the pharmaceutical, dairy and semiconductor industry, among others, are electrolytically polished. Mechanical processing remains the most important factor in determining the roughness. For example, with electrolytic polishing, Multinal Group can reduce the RA values by a few tenths (0.1 – 0.4 µm).

For the best result for your product in surface treatment

Before and after treatments

Metal pre and post treatments for the best result for your product in surface treatments

If you want to have the surface of metal objects galvanically, chemically or mechanically processed, then Multinal Group is the right place. Because in addition to a professional coating or surface treatment, we also offer metal pre- or post-treatments that contribute to achieving the desired end result. Often these metal pre- or post-treatments also offer that little bit extra without much additional costs.

When applying a coating or performing a surface treatment, we always depend on the material supplied by you. The quality of the material determines our possibilities when carrying out a surface treatment. After all, there are many types of stainless steel or stainless steel, but also steel and the country where it comes from can make the difference. With our metal pre- or post-processing, we can remove material irregularities or make material somewhat rougher, so that the layer “catches” just a little better.


Our metal before and after treatments:
  • Grinding and polishing
  • Derusting and degreasing
  • Nickel and chrome plating
  • Brushing
  • Descale
  • Shine
Steel, brass, stainless steel and plastic products

Chrome plating

Chrome plating of steel, brass, stainless steel and plastic products

Multinal Group offers an extensive range of surface treatments, of which chrome plating is frequently used.

Chrome plating is a popular surface treatment, due to its decorative properties and which also contributes to the corrosion protection and / or the application of a wear-resistant layer. Chrome plating is also a relatively inexpensive surface treatment. It is not without reason that decorative chrome plating is widely used on sanitary accessories such as toilet holders, towel hooks, soap dispensers and towel racks. In the case of furniture, chrome plating is often used on chairs, chair legs, handles, front panels, rotary knobs and (book) supports. But the lighting industry also has many examples such as spotlights, lighting plates, luminaires and decorative strips. Chrome plating is available in multiple effects such as glossy, matt or satiny and thus contributes to the added value and / or appearance of the product.


Chrome plated steel, brass, stainless steel and plastic products

In order to properly chrome-plated products such as faucets, front panels, outlets, luggage carriers and wire baskets, products are placed on a rack before it can undergo a galvanic treatment in our immersion bath. It is important to determine the visible sides of the product, so that the suspension of the product can be taken into account. The method of suspension of the product is also important in order not to create an “air bubble” during the process, so that the desired surface treatment to be applied has optimal coverage.

In addition to the suspension and determining the visible side of the product, the surface condition of the product to be treated plays an important role. This determines for 95% the result of the final quality. For example, if a product is not properly ground or polished, it will only become visible after nickel plating / chrome plating. This cannot always be prevented. It is also important that the product to be treated is easy to rinse, such as hollow spaces that must have flushing and venting holes in, for example, tubes, frames and housings.

For a nickel-plated (gloss or pearl) and chrome-plated part to offer better corrosion protection, a duplex nickel layer can be chosen. Then two different nickel layers are applied for chrome plating. This creates a “voltage difference” between the two nickel layers that produces the corrosion improvement.

Processing (machining or bending) on ​​nickel-plated and chrome-plated parts can have consequences for the quality of the treated parts. We therefore recommend that you perform the desired operations on your product before you have it chromed. View our tips for nickel plating and chrome plating of products made of steel, brass, stainless steel or ABS plastic.

Not sure which treatment is right for your products? Then we can provide you with a trial series with different treatments for your product. So that you can make a choice. You want to have a product chromed by us or have been applying this treatment to your product for years. Sometimes it can be good to take a fresh look at your article and see if there is anything to optimize in the nickel or chrome treatment. You can think of improvements in the quality of your product, realization of cost savings, or to test whether the treatment still meets the expectations of you or that of your customer. You can even contact us for special packaging instructions or requirements! Whether it is chrome plating of toilet holders, towel hooks and towel racks, soap dispensers, handles, front panels, rotary knobs, spotlights, lighting plates, fixtures, decorative strips, chairs and chair legs, sleeves, housings, frames etc. In short, whether you are an existing customer or are a new customer, we are happy to advise you.

For metal products and parts

Nickel plating

Nickel plating metal products and parts: chrome plating or for decoration

The surface treatment of nickel plating can certainly be used as an embellishment / decorative layer of a product, however, if high demands are placed on the product, the smoothness of the base material must be taken into account. Although nickel has a filling capacity, it is therefore advisable to pre-smooth the base material completely by grinding or polishing it. With these pretreatments an optimal and sleek appearance is obtained without unevenness. We can also provide grinding and / or polishing for you. We realize this effortlessly for you, without unnecessary loss of time. We provide nickel or duplex nickel plating in both serial productions to single or specialist pieces.


Properties of nickel:
  • Light yellowish precipitate
  • Good solderable
  • Magnetic coating
  • Good light reflection
  • Apply layer thicknesses of different sizes
  • Good corrosion protection
  • Not start-up resistant

Nickel and / or nickel is often used by Multinal Group as a substrate for (decorative) chrome plating, gilding or red copper. The combination of the surface treatment nickel plating and the surface treatments chrome plating and gilding reinforce each other.

For example, the nickel layer gives a certain shine to chrome, while the chrome layer ensures that the product is start-up resistant, wear-resistant and protects against corrosion. In addition to being used as a bottom layer, nickel plating can also be used as a decorative layer.

Layer thickness

When nickel plating, the layer thickness determines whether it is sufficiently corrosion resistant or not. The metal has to be pore-tight to guarantee good corrosion resistance, and not every layer and / or metal is suitable for this. If corrosion resistance is very important to you, we are happy to advise you on the options we have for your product.

Gloss, semi-gloss, matte and anti-reflection nickel

These types of nickel layers are used to embellish consumables or serve as a backing for chrome, silver or gold. The layer type is determined by the mechanical pre-treatment in combination with the nickel bath type. The matter the layer, the softer and more ductile the nickel layer is.

For steel parts and products

Electrolytic galvanizing

Electrolytic galvanizing of steel parts and products: with a low layer thickness and interesting prices

Multinal Group is the right partner for electrolytic galvanizing of steel parts and products. From electrolytic galvanizing of semi-finished steel products to finished products, we are happy to galvanize it for you.

In electrolytic galvanizing, a zinc layer is applied electrolytically to steel parts. This micron thin zinc layer gives the steel part good corrosion protection and an attractive appearance. To give this zinc layer an extra protection, the zinc layer is passivated.


We can treat the zinc layer with the following passivations:

• Passivate blue
• Iridescent yellow
(similar to the conventional yellow iridescent color)
• Black passivation with topcoat

Naturally, all these passivations are CrVI free and comply with REACH and RoHS.


In addition to galvanizing, you can choose which passivation you want and offer galvanizing in combination with powder coating.

In short, Multinal Group has the right specialists in-house for professional galvanizing or a combination with surface treatment powder coating.


Electrolytic galvanizing or galvanizing of steel has the following advantages:

• Our passivations are CrVI free and comply with REACH and RoHS
• High degree of corrosion resistance
• Zinc can be applied in very thin layers
• Galvanizing and powder coating have a very long service life
• Smooth and visual appearance

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