Jim McGill wrote:
Hi all,

Got a question for the collective wisdom. My sister and brother-in-law
recently completed a serious kitchen remodel and got an excellent 5
burner gas cook top. Big stainless bed with 3 part cast iron grid over
the top. And one minor design flaw. The cast iron grids stand on the
stainless and have little rubber feet (smell like neoprene) which keep
them from scratching up the stainless. Unfortunately if you crank the
gas up, the transmitted head turns them into vapor. Manufacturer's
answer was to send more feet, with the same characteristics. So I'm
wondering what kind of machinable nonmarring material could replace
them. I cranked out some samples from some delrin I had handy, but it
melted (not surprising - it was just a prototype). Are there any high
tech plastics that would work (probably talking 400 - 500 degrees)? Or
should I just cut to the chase and make them some polished brass feet?

PTFE can be usefull up to 500F or so.
Much hotter, and it starts to decompose.
On the "you may already have it" front, silicone sealant may work for this,
though it will go crumbly in a moderately short period.