Our cast iron products are made of spheroidal graphite cast iron “GGG” as per ISO 1083 (grade 500-7) and EN 1563. Spheroidal graphite cast iron is more widely known as “Ductile iron”. Ductile (cast) iron excels by its high resistance against corrosion and by the variety of shapes it can be cast into. By adding magnesium to normal grey cast iron, the resulting ductile iron – in comparison to grey iron – offers a notably higher tensile strength and elongation value. It also is less susceptible to shock and lends itself very well to welding.
As it has a distinctly better ratio of weight : tensile strength than grey cast iron, it allows for the manufacture of lighter covers, which are more conveniently to handle. Therefore, ductile cast iron is well suited for all applications where a high tensile strength and low weight are required - or sought - in combination.
It is common practice to coat cast iron products before they leave the factory. This coating does not have any protective effect, however, but is purely done for optical reasons. Cast iron possesses “built-in” corrosion-resistant properties which, under the influence of humidity, form a protective surface layer, preventing corrosion from developing and destroying the material – even in the presence of thawing salt.
The bright orange colour cast iron products take on after a comparatively short period, remains a thin, superficial film, which, when products are in use, converts to a dark, protective oxide coating. Hence, this superficial corrosion layer does not justify a quality complaint!
EJ Deutschland GmbH Hellerwaldstr.6 56154 Boppard Germany Phone: 0049 (0)67428722-0 Fax: 0049 (0)67428722-50