Glossary/Screw Down Crown
Screw Down Crown
A screw down crown is a type of crown that can be firmly secured to a watch case using threads, like those found on a nut or bolt. The tube is threaded on either the inside of the tube or the outside, depending on the design, and the crown is threaded opposite to this so that the two mesh together. When the crown is pushed into the case and turned on the threads of the tube as far as possible, pressure is exerted on a gasket (or series of gaskets) in the crown, and this helps to ensure the water resistance of the watch.
The Spring-Loaded Tube
Nearly all screw down crowns also feature a spring-loaded tube, that pushes the crown out away from the case when it is unscrewed. This helps to facilitate easier winding and setting of the watch.
How to Use a Screw Down Crown
To seal a water resistant watch that has a screw down crown, push in on the crown and twist it securely, in a clockwise direction, onto the threaded case tube until the crown cannot be turned any further. Do not apply excessive force.
To unscrew a screw down crown, in order to wind or set the watch, turn the crown in a counter-clockwise direction until you feel it pop-out, away from the case. You can now wind and set the watch.