Steel bars are often tested for Volumetric Defects if there is uncertainty about the quality of the product. Both mechanical and non-destructive testing (NDT) can be used to verify material quality. However, if product quality is a concern, then it is best to carry out mechanical testing first to determine the product characteristics and then confirm the absence of any volumetric defects through NDT.

Steel bars purchased in the European Union (EU) will be accompanied by a Mill Certificate to confirm that they meet the properties represented in the sales process and a Declaration of Conformity with applicable directives. Those purchased outside of the EU will often require additional verification. Volumetric defects left undetected can lead to in-service failure and so it is vitally important that these are identified before steel bars are put into use.