Bryan Olson wrote:

Amanda Angelika wrote:

A gas cooker flame is around 800C. These flames regularly come into contact
with Steel, Copper and aluminium cookware for sustained periods without
having any adverse affect on the metal at all.

The cookware never gets as hot as the flame, because the heat
gets conducted away. And how would you know if it has lost half
its strength?

You can hold a pin in a candle flame and get it to glow red and
loose stiffness.

You beat me to the flag with this post. I made many similar
points. I wish I had read this before I posted. this would have
spared me an actual experiment with a steel thread!
(I was prompted to try this when I read what the temperature
of a candle flame is)