Perhaps you missed it but I made my qualifications known, 2 degrees, technical school graduate, additiional classes in forensic metallography, materials sciences instructor. I recently retired by was employed at the Nat'l Inst. of S & T for a little over 20 years. Spent time in R & D, technical specification and writing, testing and analysis, destructive as well as NDT programs. Numerous other achievements and activities as you can imagine as well as numerous and continued participation in the 3 wtc buildings as well as the Pentagon crash. I also worked in conjuncture with the NTSB and did my fellowship with the ASTM.
Yes i missed that.
So maybe you could explain in simple terms how steel can retain its strenght when heated by an office fire?