Point made, my bad, my apologies to Minadin.
NIST did conduct tests for NYC but those tests were of generalized components/assemblies, NOT specifically the components used in the construction of the WTC.
Your apology is accepted.
However, in the interests of being as factually accurate as possible, I think that you might be swinging too far to the other side of the argument, in your second statement.
(I am assuming you meant the UL performed tests for the NIST; don't know of the NIST performing any tests for NYC)
As far as I am aware, the tests conducted by UL at the behest of the NIST as part of their WTC 1/2 collapse investigation were of assemblies built to the specifications of the ones which were used in the construction of the Twin Towers. It would make sense, of course, that they would want the test to be as true to reality as possible, so they should have used the same arrangement of components as what actually did go into the buildings. Which is, by the way, what they normally do, and they're very good at it.
I know that you have dropped the point, but I do think that it's important to clarify what the various different terms are in relation to these tests, how they perform them, what they are testing, and how they evaluate the performance of certain materials and applications.
The steel components are, of course, the structural members that are being protected by the fire insulative material. It might be a bar joist, a steel stud, a column or wide flange beam. These are usually standard building materials that are more or less mass-produced, and we know what their properties are supposed to be, unless there is some material or manufacturing flaw, or some sort of physical damage.
The assemblies are a combination of one or more steel components, put together in the manner that they would be found in finished construction, with the fireproofing material(s) and other items, such as finishes or hardware. Various assemblies will be built completely differently from each other. For instance, one example might be a section of standard office partition wall, with 3-5/8" metal studs separating 5/8" drywall on each side, with sound batt (Pink Panther style) insulation in between. Another assembly, such as the ones that I believe UL tested for NIST, would be to have a section of 3-1/2" poured concrete over a corrugated steel deck, with 29K12 (2'-5" deep, chord size 12) steel bar joists attached to the underside, with spray-on fire insulation coating both the bottom of the steel deck and the bar joists. This is what Architect typically refers to as a composite floor system.
The tests are done by subjecting the entire assembly to heat / fire in a controlled environment such as a furnace, for a specified amount of time and / or temperature, or until the assembly fails, in some cases. It depends on the requirements of the test, and those can vary based on what they are looking for specifically.
Even though the entire component is subjected to the test, what they are actually testing is the effectiveness, durability and fire resistance of the materials applied to the structural components in a given design. The best way to discern this is by evaluating the one known in the experiment, which is the steel component(s). So, when you hear about how such-and-such steel performed in the testing of an assembly, keep in mind that they were not so much testing the steel, but the materials applied to it, and are referring to the steel as a benchmark to gauge how effective those applied materials were able to protect it.
