Plastic knob on a Cousances pot

Hi all,

I've got a Cousances pot from an old relatives and would like to make bread in it. The problem is the plastic knob - if in the right material - don't sustains temperature above 200°C (right?) and bread making is around 250°C.

Can I just replace the knob with some steel nut I get from the hardware store? I'm not sure I can get those replacement lecreuset ones at the moment. Or maybe is there an alternative solution?

Thanks!