A crown in watchmaking is a small, often knurled knob located on the side of a watch case, used for setting the time and date and, in some watches, winding the mainspring. There are two primary types of crowns: screw-down and push-pull.

A screw-down crown is designed to enhance the water resistance of a watch. It features a threaded stem that screws into the case, creating a tight seal that prevents water and dust from entering the watch. This type of crown is commonly found on diving watches and other timepieces designed for water sports, as it provides an extra layer of protection against moisture. To adjust the time or date, the wearer must first unscrew the crown before pulling it out to the desired position.

In contrast, a push-pull crown does not screw into the case. It is simply pulled out to set the time or date and pushed back in to secure it. While easier to operate, push-pull crowns generally offer less water resistance compared to screw-down crowns. They are typically found on dress watches and other timepieces where water resistance is not a primary concern. Both types of crowns play a crucial role in the functionality and durability of a watch, influencing its usability and resistance to environmental factors.