To ensure the service life and quality of our wood screws, they are protected against corrosion. But which corrosion protection you need depends on the application and the environment. You can get screws from pgb-Europe in the following corrosion-resistant coatings and materials:
Our electrolytic galvanised screws have a steel core covered with a layer of zinc. This makes them less sensitive to corrosion. The zinc layer thickness on the steel screws is usually 5 to 8 microns. Because the production process of yellow-galvanised screws, with Chrome VI, is too harmful to the environment, they are gradually being replaced by white-galvanised screws. These are coated with the more environmentally friendly Chrome3+. You can also find the symbol of 'Cr3+' on the packaging of our screws. Galvanised screws may, as a rule, only be used for indoor applications, in dry environments with low humidity.
At pgb-Europe, we are constantly innovating to make our products even better. That is why we developed the BlueTop coating. This involves applying an additional sealant on top of the galvanisation. We gave it to the Hapax screws, because these screws are used in more demanding applications. The screws with a BlueTop coating are ten times more resistant to rust in a salt spray test. They can therefore be used in applications where they come into contact with high humidity, but are not exposed to direct contact with water. So you can use them on outdoor covered structures such as a carport or roof constructions.
BlackTop Coating is a deep black surface treatment with high corrosion resistance, a low layer thickness and an even black gloss effect. It is the ideal surface treatment for those looking for a black finish with high corrosion resistance. Thanks to the corrosion-resistant properties of the coating, products and fastenings remain protected for longer against various environmental factors, such as rain and wind. So you can use your black garden fittings without any problems.
If you use the screw in a humid environment, or if it comes into direct contact with water, then it is best to choose stainless steel. There are different types of stainless steel. Here again, it is very important to take into account the environmental factors in which the screws will be used.
Stainless steel C2 or AISI 410
Stainless steel type C2 or AISI 410 can be found with our deck screws. They are the least corrosion-resistant of all types of stainless steel screws. On the other hand, these screws have the best mechanical properties because they have the highest carbon content in the steel. You should use these decking screws when there are no other factors that could affect the steel, such as acids in certain hardwood areas or environmental factors such as salt or chemicals. Do not use this type near swimming pools or the coast.
Stainless steel A2 is the most common type of stainless steel used in fasteners. They combine excellent corrosion resistance with good mechanical properties. They also have good resistance to acids in tropical and European hardwoods. That is why our range of A2 screws includes not only deck screws, but also wood construction screws and chipboard screws. You can use them in environments with high humidity or exposed to moisture, but they are not chemically resistant.
Where there are extra factors that can cause accelerated oxidation, you should choose stainless steel A4 screws. These are mainly environments where chemical factors play a role, such as around swimming pools, in the chemical industry, but also in coastal areas, where salty sea air can affect the steel. Furthermore, certain acids in hardwood species can also cause accelerated oxidation. When using these types of wood, you should therefore ask the wood supplier whether the use of Inox A4 screws is necessary.
