Dè eile a chanar ris na seamannan dall ceann oblate dùinte?

Faodar seamannan dall ceann oblate dùinte a ghairm cuideachd:

Seamannan dall ceann cruinn dùinte dùinte, seamannan tarraing ceann cruinn còmhnard dùinte, seamannan tarraing ceann cruinn dùinte dùinte, seamannan tarraing cruinn dùinte dùinte.

https://www.yukerivet.com/news/what-are-the-surface-treatment-methods-for-anti-corrosion-of-closed-countersunk-head-blind-rivets/