Class 15 Bobbins: Plastic vs. Metal, What Fits

Class 15 is the most common drop-in bobbin standard on home sewing machines. Here's what it is, which machines use it, and how to choose between plastic and metal.

What Class 15 is

Class 15 (sometimes called Type A or 15J) is a top-loading, drop-in bobbin measuring 20.3mm outer diameter, 6.1mm inner diameter, and 11.5mm (7/16 in) height. It's used across many Janome, Kenmore, Brother, Elna, Singer, and Baby Lock machines with a top-loading bobbin system.

Plastic or metal — how to choose

Plastic is the standard choice: lightweight, and clear enough to see your remaining thread without opening the compartment.

Metal is heavier and more durable, but it's only the right choice if your machine's manual specifically calls for a metal bobbin. Don't use a metal bobbin in a machine designed for plastic — check your manual first.

Sewphee's Class 15 options

See the full Class 15 Bobbins collection and the Metal Bobbins collection.

Still not sure?

Check your machine's manual for the bobbin class, or send us your machine model and we'll confirm the fit before you order. Broader guide: Sewing Machine Bobbins: The Complete Guide.