Metal testing is a process that involves the analysis of metal samples to determine their composition and properties. The term 'metal testing' can refer to a variety of tests, including spectroscopy, X-ray fluorescence, and chemical assays. The most common type of metal testing is an ASSAY, which is a laboratory test used to measure the amount of a particular element or compound in a sample. Assays are used to determine the purity of metals, as well as to identify any impurities present in the sample. Metal testing is an important part of the manufacturing process, as it ensures that the metal products produced meet the required standards.