In an alloy steelworks producing
and bars for further processing, the properties stated for the steel are the properties it will have after the final heat treatment. The billets do not have those properties, as they have had an uncontrolled slowish cool from rolling temperature, so are in some unspecified state.
[This contrasts to the majority tonnage of steel production for structural steels, pipeline, auto-body sheet steel, etc, where the steel is delivered in the final condition, with the properties stated]
It follows therefore that an alloyed steels steelworks selling billets
must have a Test House where the final heat treatment is simulated on
samples prepared to about the size of the components which will be
The properties measured on these steel samples in tests typical including tensile, notch-impact, hardness, etc are what is certified for that batch of steel
Other characteristics certified are invariably the composition in all alloying elements which could influence properties (a long list), and often the heat-treatment response in a standard test (the "Jominy" hardenability test, which measures the hardness-profile of an end-quenched bar sample of the steel, about which abundant information is available on-line).
The range of tests done is much more extensive and covers many more issues than I have indicated in this very brief overall indication of the industriousness of a Test House.
(R. Smith, 31Dec2017)