Bolts for screen, why can't I find plastic ones?

[Arfa]

Looks for some bits to patch up my bike after recent off. Screen had popped off, sheering all the heads off the plastic bolts in the process. On plus side the screen itself is still in good nick. So I'm looking for a set of 7 bolts to stick it back on. But looking on ebay, they're all aluminium, stainless steel or titanium! Yeah, they'll do the job, but if the same thing happens again, they won't snap, the screen will. So thinking sticking with plastic maybe the best plan.

But where can I get some? Am I correct in saying they're just standard M5 bolts? Could just hunt down some generic bolts.