Apple Final Cut Pro X (10.0.9) - Manual (Page 124)

Chapter 8 Edit your project 124
2 Move the skimmer to the frame in the clip where you want to cut, and click.
Blade tool
Tip: You can also cut clips while playing back your project. To cut clips on the fly, press
Command-B at any time while your project plays back.
An edit point appears where you clicked, and the clip is divided into two clips.
New edit point
Cut all clips at once
You can use the Blade All command to cut all primary storyline clips and connected clips at the
skimmer or playhead location simultaneously.
1 In the Timeline, move the skimmer to the frame where you want to cut.
2 Choose Edit > Blade All (or press Command-Shift-B).
All clips at the skimmer position are cut.