These tests are intended for rapid, inexpensive and usually non-destructive and on-site sorting of grades of stainless steel. They are particularly useful for sorting products when, for example, bars of grades 304 and 303 have been accidentally stored together, or grade 304 and 316 sheet offcuts mixed.

These tests are extremely useful, but it is important to realise that they have limitations; they cannot sort one heat from another of the same grade, and there is no easy way of sorting certain grades from each other. For instance, it is not possible to readily sort 304 from 321, 316 from 316L or 304 from 304L. The Molybdenum spot test therefore indicates that a piece of steel contains Mo, but does not alone indicate 316. In the absence of other knowledge the steel could be 316L, 2205 or 904L etc.

The simple tests described may assist in grade identification and product sorting. Other, more complex tests can also be carried out; these can involve several chemical reagents, hardness tests or checking response to heat treatment. In most cases, however, if these simple tests are not sufficient to identify the product it is best to have a full spectrometric analysis carried out by a competent laboratory.

The need for these sorting tests can be reduced if original product identification is retained. Product colour codes, tags and stickers and stamped or stencilled Heat/Grade/Specification markings should be retained as much as possible.