Gịnị bụ ihe dị iche n'etiti countersunk isi rivets na gburugburu isi kpuru rivets?

Gburugburu isi kpuru rivets adịghị mkpa chamfering, ha ga-esi n'elu pụta mgbe riveting, mgbe countersunk isi kpuru rivets kwesịrị chamfered site 120 °, na ha ga-na otu ụgbọelu dị ka efere mgbe riveting.