Steel is the most widely used metal of our time. There are different methods to protect steel against corrosion. The chosen protection depends, naturally, on the environment where the product is to be mounted. Corrosion stress classification and required surface treatments defined by the standards SFS-EN ISO 12944-2.
Hot galvanized sheet metal
Products with hot galvanizing are made of zinc-coated steel band. These products are also called pre-galvanized products. Thickness of the zinc coating of these products is at the minimum 20 µm. Hot galvanizing of sheet metal products is performed according to the standards EN 10327, ASTMA 875 and DIN 17162.
The products can be used in environmental stress categories C1 and C2. Typical environments are dry premises, such as offices or business buildings, shopping malls, markets, schools, hospitals, industrial halls, storages, sports halls etc.
Hot dip galvanizing
Hot galvanized products are made of sheet metal without surface treatment. A final product, for instance a whole cable ladder or a part of it, is dipped in liquid zinc after pre-treatment. These products are also called products galvanized by dipping. Zinc coating covers the whole product, including cut edges and welded seams. Thickness of the zinc layer of these products is min. 55 µm. Hot galvaninzing treatment meets the requirements of the standard SFS 1461, which is equal to the older standards SFS 2765 and DIN 50976.
The products are suitable for environmental stress categories C1, C2, C3 and C4 which are typically outdoor facilities or production and industrial premises with high contents of humidity and impurities.
Surface treatment PEX (Duplex treatment)
In the Duplex treatment the product is pre-cleaned, powder painted and finally hardened in oven.
The Duplex treatment provides additional protection to a hot galvanized product which can be necessary in extremely corrosive surroundings. The Duplex treatment gives a customer a choice of colour in all RAL tones. The standard colour of the PEX products is white RAL 9010.
PEX products can be used in premises of the environmental stress categories C1 and C2. The PEX products KS80 and KSF80 can be used in premises of the environmental stress categories C1, C2, C3, C4, C5-I and C5-M.
Panted sheet metal
Paint coated sheet metal products are made of pre-galvanized and painted steel band. The surface is covered with polyester paint which has a good resistance against climate, corrosion and wearing. These products can be used in premises of environmental stress categories C1 and C2 which typically are dry premises, such as offices, business buildings, shopping malls, markets, schools, hospitals, sports halls etc.
The standard colour tone is RAL9010 white. The white KRA-xxx M cable shelves are additionally covered with removable plastic film to protect the product during transportation and installation.
Stainless steel AISI 304 (RST) and acid proof steel AISI 316L (HST)
Products made of stainless steel and acid proof steel are used in extremely corrosive environmental conditions where hot galvanizing is not enough. Both materials can be used both outdoors and indoors.
These products can be used in premises of environmental stress categories C3, C4, C5-I and C5-M. Typically they are installed in premises of chemical industry and paper mills as well as in premises with special hygienic requirements, such as dairies, slaughterhouses and other facilities of food and medical industry.
The choice between stainless steel and acid proof material depends on several factors. The most relevant element is the chemistry of the environment, i.e. the effective contents and combounds. In general it can be stated that acid proof material gives a better protection against climate born corrosion and it is better suitable for industrial environments and sea climate. Use of acid proof material is also required in conditions with high contents of chlorides.