Know Your Notions™

April, 2004

Know Your Dritz® Class 15 and Class 66 Bobbins

Bobbins are an essential part of good stitch formation. It's important to use the right bobbin in your sewing machine. The purpose of a bobbin is to hold the bobbin thread. The bobbin thread interlocks with the top thread to form a stitch.

The bobbin case holds the bobbin and the bobbin thread. It must be free of lint, dirt and rust so it can release the bobbin thread evenly. There are two standard types of bobbin cases: Removable (oscillating) and top drop-in.

There are two standard types of bobbins: Class 15 for Removable (oscillating) bobbin cases and Top Drop-In Bobbin Cases and Class 66 for Top Drop-in Bobbin Cases.

Bobbins have a notch on the inside opening. This locks the bobbin onto the bobbin winder. The hole on top of the bobbin enables thread to be fed from inside the bobbin to the outside so it can be held taut when starting to wind the bobbin.

Selecting Bobbins:

Winding Bobbins:


Three Dritz class 15 bobbinsDritz® Class 15 Bobbins

Note: The Dritz package states for "removable bobbin cases," but our new research indicates that the Class 15 Bobbin can be used for both "removable and drop-in" bobbin cases. We will update our packages in the near future.

Sewing Machine Compatibility

Some of these machines use a Class 15 Bobbin
Baby Lock - Fits most lower end machines.
Brother - Fits most computerized machines.
Riccar - Fits a few.
Simplicity - Fits most lower end machines.
Singer – Class 15 machines.
White - Fits most machines.

Fits NONE of these machines:
Bernina, Elna, Husqvarna/Viking, Janome/New Home, and Pfaff
Machines made in Sweden, Germany and Switzerland have their own special bobbins.


Three Dritz class 66 bobbinsDritz® Class 66 Bobbins

Sewing Machine Compatibility

Fits Some of these machines:
Baby Lock
Singer – Class 66 machines

Fits NONE of these machines:
Bernina, Elna, Husqvarna/Viking, Pfaff, Janome/New Home