How big are the rivet holes on Tramontina Machets?

[TXoutback]

I might want to drill out the rivets on my beloved tramontina 18" Machete.

I realize new rivets will cost more than a new machete, but I thought I might save $17 and ask here if anyone knows the diameter of rivet to buy, instead of just buying a donor machete to find out.

Thanks!