Have you ever seen a watch without a removable case back and wondered how you get the movement out?? In this post I will show how to remove a two piece split stem from a watch.

This is a typical screw back watch case. Notice the 6 cutouts that will fit a standard case wrench
Standard watch case wrench

Some cases were designed as a “one piece case” that does not have a removable back. With a watch like this, How do you remove the movement?

Omega is famous for their one piece case designs on their Seamaster watches

The first step to removing the movement is to remove the crystal. This is done with the help of a crystal lift. This is a very cool tool the grasps the outer edge of a crystal, then by turning the handle, the crystal is compressed making it a tiny bit smaller so that it can be removed.

Crystal lift grasping the outer edge of a crystl
Crystal lift showing crystal and turnable handle

Once the crystal is removed, on this model, the inside movement retention ring needs to be turned to “unlock” the movement from the case.

Turning the movement retainer ring.

Now comes the tricky part, cutting the two piece stem to remove it.

crown before removal

I normally use a standard pair of cutters to gently pry apart the crown/stem to remove it. You place the cutters on either side of the case tube, gently apply pressure and “cut” the stem loose

standard cutters
Shows the Male half of the split stem
Female half of the stem that goes in the crown
Solid case showing the movement retention ring
The classic design of the Omega Seamaster is only possible because of the design of the two piece stem

Mark Sirianni Watch Repair

25 Fraley St.

Kane, PA. 16735


[email protected] email