Gängorna låser inte bara kronan. De hjälper till att skapa en tätare packning.Nej, gängorna tätar inte. Gängorna låser bara kronan. Men ju mindre påfrestningar på packningen, ju bättre, såklart.
As part of his Oyster case design, Hans Wilsdorf also patented the screw-in crown. The advantage of the screw in crown is the ability for it to seal against a rubber gasket. Although some crowns already possessed some type of rubber seal, the combination of a threaded stem compressing against a rubber o-ring made the seal much more water tight.