Galvanizing – process and costs in comparison

What advantages does galvanizing offer over painting?

While ordinary coatings such as paint or powder coating protect a component by preventing a reaction with oxygen (oxidation), galvanizing also offers one cathodic protection against corrosion. This is the steel even with minor damage such as scratches, cuts, holes or edges are still protected from corrosion.

Galvanized steel can be exposed to the elements for many years without any problems and even minor damage has no effect on the stability of the steel. In the case of painted components, however, damage must be repaired to avoid rusting.

What is meant by cathodic corrosion protection?

The zinc of the coating is ignoble than the underlying steel structure. The zinc layer therefore acts as a so-called sacrificial anode, which oxidizes first. This means that the underlying steel structure is protected from corrosion for as long as until the zinc layer is used up. This protection exists even if the surface is damaged and lasts for a very long time.

Can galvanized components rust?

Galvanizing offers very good corrosion protection, but rust can occur over time. The following points must be taken into account when using galvanized components:

  • To avoid corrosion should Major surface damage reworked become. You can use zinc dust paint for this. 
  • The Surroundings of the components has an influence on the service life of the zinc layer. Moisture or salts increase conductivity and promote corrosion. This is particularly important to pay attention to in coastal regions.
  • contact corrosion is also favored by a higher conductivity of the environment. To ensure that no contact corrosion occurs, the choice is important Fasteners and when used different materials pay attention to the electrochemical potential. One of the problems is the connection with Copper or Stainless Steel. The mass of the zinc layer as a sacrificial anode also plays a role. Stainless steel screws for fastening a galvanized sheet are generally not a problem, but if you fasten a stainless steel sheet with a galvanized screw, corrosion occurs.

Further details on professional galvanizing and the handling of galvanized steel structures can be found in the standards attached at the end of the text.

What galvanizing processes are there?

Hot-dip galvanizing

During hot-dip galvanizing the... steel construction or the components in one Bath of liquid zinc submerged. The temperature of the zinc is around 450°C. The Zinc layer thicknesses are between 50 and 150 micrometers. In continuous strip galvanizing systems, such as those used for galvanizing steel sheets or pipes, significantly smaller zinc layer thicknesses are produced.

Large components are suspended individually and dipped into the zinc bath. Small components are centrifugally galvanized. The components are immersed in the zinc bath in baskets and the excess zinc is then separated off in a centrifuge.

You can see how hot-dip galvanizing works in the accompanying explanatory video about hot-dip galvanizing Institute for hot-dip galvanizing.


By downloading the video you accept the privacy policy of YouTube.
Read more

Load video

What should be taken into account when hot-dip galvanizing?

For hot-dip galvanizing, the components must be prepared professionally. It must be ensured that the liquid zinc gets to all parts of the component and can also flow away again. Become this Inlet and ventilation openings drilled. The components must also be clean before galvanizing. Varnish, oil and other residues must be completely removed. Cleaning can also be carried out at the galvanizing plant.

The warming can cause deformations come. This is particularly problematic with welded components, as well as with thin-walled and large-area sheets. Tight tolerances must therefore be reworked. Threads must be recut after galvanizing.

During hot-dip galvanizing, the parts are immersed in a bath of liquid zinc. It is completely normal that the Zinc layer thickness is not the same everywhere. The surface cannot be compared to a painted surface. Defects may occur due to the process and must be tolerated in accordance with the EN ISO 1461 standard. Sharp edges and depressions are particularly problematic.

Hot-dip galvanized components can then also be powder-coated or painted. In order to get good surface quality, they must be prepared after galvanizing. Defects can be eliminated by fine plastering and the surface straightened. In order for the paint to stick to the zinc layer, the surface must be chemically treated.

Where can you find suppliers of hot-dip galvanizing?

You can find some on the directory Providers of hot-dip galvanizing from Austria and Eastern Europe. You can find a list of hot-dip galvanizing plants in Germany at Hot-dip galvanizing industry association. In order to keep the transport costs for galvanizing low, it is recommended to choose a galvanizing plant close to the supplier or close to the customer.


When galvanizing, the components are not immersed in a zinc melt, but rather in a Electrolyte bath. The steel structure or the components are used for galvanizing as a cathode. One serves as an anode Pure zinc electrode. By applying voltage, a layer of zinc is deposited on the steel structure.

The thickness of this zinc layer can be controlled by the duration of the process. However, it will Zinc layer not uniformly thick everywhere. As a rule, this is how you achieve it Layer thicknesses between 5 and 40 micrometers, significantly less than with hot-dip galvanizing.

The Corrosion Protection Galvanizing is therefore fundamental worse than hot-dip galvanizing, but the process also offers many advantages.

What are the differences between electrogalvanizing and hot-dip galvanizing?

  • Due to the small thickness of the zinc layer Dimensional accuracy the components are better with galvanizing than with hot-dip galvanizing. 
  • Threads do not need to be reworked when galvanizing.
  • Galvanizing can also be used for temperature-sensitive workpieces be applied. During hot-dip galvanizing, these would warp due to the heat.
  • To further improve corrosion protection, the components can be chromated or powder-coated.

Hot-dip galvanizing offers significantly better corrosion protection than galvanizing. When it comes to the corrosion resistance of simple components, hot-dip galvanizing is the best choice. If the components need to be precise or have a surface that is as uniform as possible, galvanizing is more suitable. Galvanizing is also advantageous for components that have a strong tendency to warp.

Spray galvanizing

During spray galvanizing, zinc wire is melted and, like painting, applied to the workpiece using compressed air. The layer thicknesses are similar to those of hot-dip galvanizing and are between 80 and 150 microns. The main disadvantages are that it... not in cavities can be applied and that the workload is comparatively high. For that can Spray galvanizing can also be used on components that are not suitable for hot-dip galvanizing can also directly on construction sites be performed. Spray galvanizing does not require any drying time because the zinc solidifies immediately.

When hot-dip galvanizing, the size of the components depends on the dimensions of the zinc bath. Many galvanizing plants can only galvanize components up to 8m in length, some even up to 15m. Spray galvanizing can also be used to coat components that are too large for hot-dip galvanizing.

The layer thickness can be individually adjusted during spray galvanizing. A component can have a higher layer thickness in important places.

How much does galvanizing cost in 2023?

The costs for galvanizing depend on the respective process. Basically, in the industrial environment, components made of profiles or pipes cost 0,25 – 0,6€ per kg of finished steel structure to be expected. Galvanizing smaller components is significantly more expensive. Private users with small quantities also have to expect significantly higher prices.

For thin-walled components such as sheet metal, the price also depends on the geometry. You can find a more precise estimate of the costs under the respective procedures.

There are also transport costs and costs for the preparation and follow-up of the components.

Compared to alternative materials and processes, galvanizing is very attractive in the long term. Galvanized components cost less than stainless steel components and the corrosion protection provided by galvanizing is higher than with painted components. Galvanizing is often the cheapest alternative in the long term, especially for outdoor applications. In this article you will also find examples of this Price per kg of steel structure for different components.

Hot-dip galvanizing costs

The cost of hot-dip galvanizing depends on the order volume and the size and complexity of the components. In addition, the prices for galvanizing depend heavily on energy costs and the price of zinc. The price of zinc is currently very high, which is why many galvanizing plants had to increase prices in 2022.

The Prices for hot-dip galvanizing from very heavy steel structures start at approx. 0,40 € / kg. For light steel construction in an industrial environment, one kilogram of hot-dip galvanizing costs around €0,60. Centrifugal galvanizing for smaller components under 3kg costs around €1,30/kg for industrial customers.

For small quantities for private customers you have to expect prices of more than 1€/kg.

Additional costs of 0,20 – 0,30 €/kg can be expected for fine plastering.

Costs for spray galvanizing

The costs for spray galvanizing are: approx. 10-12€/m². There are also costs for the previous sandblasting. These depend very much on the nature of the surface and the component geometry. Furthermore, the components must be further coated or painted after spray galvanizing. The amount of work involved in spray galvanizing is very high, which is why labor costs are a decisive factor in spray galvanizing.

Costs for galvanizing

The Costs for galvanizing depend primarily on the layer thickness and start at around 0,25 € / kg. In many applications, galvanizing is cheaper than hot-dip galvanizing. However, for the same layer thickness, galvanizing is much more expensive than hot-dip galvanizing.

Is galvanizing cheaper abroad?

Unlike welding, the cost of galvanizing abroad is usually no lower than in Western Europe, so painted structures in these countries are significantly cheaper than galvanized structures. In Western Europe it is the other way round, where galvanized steel components usually cost less than painted ones.

Galvanize the components yourself

Build your own galvanizing systems

For craft needs and for small items such as jewelry, there are DIY kits for galvanizing at home. These are generally used for silver or gold plating, but with the appropriate electrolytes and a suitable zinc anode they are also suitable for galvanizing. In addition to electroplating baths, there are also simpler hand electroplating devices.

Zinc dust paint or liquid zinc

Zinc dust paint and liquid zinc are easy ways to retrofit or repair cathodic corrosion protection. It is a primer that contains fine zinc particles. This zinc dust provides the corrosion-inhibiting properties. They are available both for painting and as practical zinc sprays. With sprays, it should be noted that the zinc layer thickness is smaller.

Further questions about galvanizing

How much does galvanizing railings cost?

The cost of galvanizing railings is approximately €0,65 per kg. The price also depends on the surface. The larger the surface of the component, the more zinc is required. Railings made of wide flat bars have a fairly large surface area of ​​approx. 1m2.

Last revised on September 22, 2023 by Andreas Janisch

How much does hot-dip galvanizing and powder coating cost?

Galvanizing is usually billed based on weight, powder coating based on the area of ​​the components. Powder coating costs around 15-20€/m on an industrial scale2. A price example for a steel beam (support HEA400 with stiffening plates and head plate, length: approx. 4,5m. Weight: 620 kg, surface: 14m2):

  • Galvanizing: 620kg x 0,40€/kg = 248€
  • Fine plastering: 620 kg x 0,25€/kg = 155€
  • Powder coating: 14m2 x €17,50/m2 = 245 €
  • Total: €648

There are also transport costs if galvanizing and powder coating are not carried out in the same company. These guide prices are for projects starting from around 20 tonnes. The costs would be significantly higher for individual providers.

Last revised on September 22, 2023 by Andreas Janisch

What is yellow galvanizing?

Yellow galvanizing is actually not a separate galvanizing process. When yellow galvanizing, the parts are first galvanized and then chromated. This further improves corrosion protection. Yellow galvanized components are used for screws and furniture fittings, in mechanical engineering, in electrical appliances and in automobile construction. Yellow galvanizing is rarely used in steel construction. Here you will find a very good video on yellow galvanizing.


By downloading the video you accept the privacy policy of YouTube.
Read more

Load video

Last revised on September 22, 2023 by Andreas Janisch

Further reading on galvanizing steel:

Maaß, Peter / Peißker, Peter

Hot-dip galvanizing manual 4th edition 2016

Wiley-VCH, Weinheim


  • DIN EN ISO 1461 – Zinc coatings applied to steel by hot-dip galvanizing (piece galvanizing) – requirements
    and testing – and associated supplement 1
  • DIN EN ISO 14713 – Protection of iron and steel structures against corrosion – Zinc and aluminum coatings –
  • DIN EN 2063 – Thermal spraying – Metallic and other inorganic coatings – Zinc, aluminum and their alloys (ISO 2063:2005)
  • COST EFFECTIVE GALVANIZING IN REMOTE AREAS – Mr. Stuart Anthony McInally – University of Queensland 2013
  • Wikipedia

More information and updates on costs in steel construction - subscribe to our newsletter!

* Indicates required

About the author

  • Andreas Janisch


    Andreas Janisch, founder of, is an industrial engineer with more than 15 years of experience in mechanical engineering, plant construction and construction....

    view profile

Last revised on September 22, 2023 by Andreas Janisch