Ngaba i-countersunk head rivets ifuna imingxunya edibeneyo?

Ngaphambi kokusebenzisa i-countersunk evulekileyo yentloko yokutsala i-rivet, kuyimfuneko ukwenza umngxuma wokubala kwi-plate kuqala, ngaphandle koko kuya kuba lula ukungalingani emva kwe-riveting.