Am feum an toradh a bhith air a chur fodha gus na bioran ceann cruinn a thoirt a-mach?

Chan eil e riatanach tuill leudaichte a tholl gus rioban le cinn chruinn falamh a tharraing.

https://www.yukerivet.com/news/do-countersunk-head-rivets-require-countersunk-holes/