SBH radiators are manufactured from 100% stainless steel (Grade 304).They will not rust or corrode. They are pressure tested with air to 10bars under water. Stainless steel has the major advantage of being totally impervious to water, therefore enabling its use in any domestic heating system, both direct/open or indirect/closed. Stainless steel has an extremely durable surface, so it will with stand a high degree of wear and tear
