The oval metallic-appearance oven knobs are made of plastic.
Over time heat distorts then until they no longer grip properly.
I purchased a replacement on-line via Amazon, only to discover on receipt
that it was 29.97mm in length whereas what I need was 34.43mm.

No quibble from Amazon but none of the adverts for these things give the
dimensions! Worse, it seems you can only get them if you buy the complete
switch!

I do hate globalisation.

Rant over.





--
Mint 19.1, kernel 4.15.0-45-generic, Cinnamon 4.0.9
running on an AMD Phenom II X4 Black edition.