This part of ISO 14713 provides guidelines and recommendations regarding the general principles of design that are appropriate for articles to be sherardized for corrosion protection. The protection afforded by the sherardized coating to the article will depend upon the method of application of the coating, the design of the article and the specific environment to which the article is exposed. The sherardized article can be further protected by application of additional coatings (outside the scope of this part of ISO 14713), such as organic coatings (wet paints or powder coatings). When applied to sherardized articles, this combination of coatings is often known as a "duplex system". General guidance on this subject can be found in ISO 12944-5 and EN 13438. The maintenance of corrosion protection in service for steel with sherardized coatings is outside the scope of this part of ISO 14713. Specific product-related requirements (e. g. for sherardized coatings on fasteners or tubes, etc.) will take precedence over these general recommendations.