VSB currently stocks virtually all screws for external use, surface treated with Zincotech® surface finishes. Depending on the application, the most suitable Zincotech® surface treatment is selected for each product group.
Surface treatments Zincotech®Au and Zincotech®Ag are approved for Corrosivity Class C4 (RISE report SP PX14769).
Corrosivity classes are a division of different environments that are based on the degree of corrosion, degradation per unit of time that metals are expected to be exposed to in such environments.
Corrosivity Class C1 – Very Low
Indoors: Heated spaces with dry air and insignificant amounts of pollution, e.g. offices, shops, schools, hotels etc.
Corrosivity Class C2 – Low
Outdoors: Atmosphere with low levels of pollution. Rural areas.
Indoors: Unheated spaces with varying temperatures and humidity. Low frequency of moisture condensation and low air pollution, such as sports halls, storage rooms etc.
Corrosivity Class C3 – Moderate
Outdoors: Atmosphere with a certain amount of salt or moderate amounts of air pollution. Urban areas and lightly industrialised areas. Areas partly affected by coastal climate.
Indoors: Spaces with moderate humidity and a certain amount of air pollution from production processes, such as breweries, dairies, laundries etc.
Corrosivity Class C4 – High
Outdoors: Atmosphere with a moderate amount of salt or significant amount of air pollution. Industrial or coastal areas.
Indoors: Spaces with high humidity and high levels of air pollution from production processes, such as chemical industries, swimming pools, shipyards etc.
Corrosivity Class C5-I – Very high (Industrial)
Outdoors: Industrial areas with high air humidity and aggressive atmosphere.
Indoors: Spaces with almost permanent moisture condensation and high levels of air pollution.
Corrosivity Class C5-M – Very high (Marine)
Outdoors: Coastal and offshore areas with a large amount of salt.
Indoors: Spaces with almost permanent moisture condensation and high levels of air pollution.
Corrosivity classes according to SS-EN ISO 12944-2 as well as examples of typical environments.