The body of a wrist watch, called the watch case, houses its delicate internal workings and the framing of the watch face. To conceal the tiny and crucial parts inside, the case is held closed using a variety of back types, which ensure the back will not move accidentally or inadvertently. Each type of watch back, like a snap back, has its own method of removal and proper method of replacement. By closing your watch correctly, you ensure safe handling of your watch while avoiding any potential damages to the workings.
Choose an adapter from your watch case tool that is just slightly smaller than the back of your watch. You can hold the back of the watch up to each of the adapters, until you find the one that is the right size for your watch. Push the selected adapter into the upper jaw of the tool until it snaps into place.
Set the lower plate onto the bottom jaw of the tool and pick out a support ring. The ring must be large enough to sit on the face of your watch around the outer edges, but not big enough to slip around the watch face. Fit the plastic ring onto the plate in the lower jaw of the tool to create a support for the front of the watch during setting.
Lay your watch in the watch case tool with the open back facing upward. Place the watch face squarely on top of the plastic ring in the lower jaw, with the straps laying flat on either side of the watch.
Arrange the gasket inside the watch case as it was when you opened the watch. Make sure it is lying flat and flush inside the case or the back will not reattach properly.
Find the small marking on the interior rim of the watch back and match it up with the similar mark on the inside of the watch case. Place the watch back on top of the watch with the marks matching up. Make sure the exterior side of the watch back is facing upward.
Apply pressure to the case tool handle until the jaw compresses the back into place. You will hear the case snap together to know when to release the tool. Work the tool gingerly to avoid damaging your watch case or workings.
Ask a professional if you could watch them open and close you watch once to get a better idea of how your watch functions and how it should be treated.
Do not handle any of the internal parts of your watch with bare hands. The natural oils in your skin can cause the workings to jam or malfunction.