The Simthread Company has been a dedicated Brother embroidery thread supplier for more than 35 years and they have a reputation for producing a superior quality product. The tri-lobal construction has a high luster and vivid color that closely matches those produced by Brother.

What Size Bobbins Will Work In My Home Embroidery Machine?

There are 3 different sizes of machine embroidery bobbins that we sell, style L, M, and A (also know as Class 15). These do not stand for large and medium.

The Class 15 (A Style) Bobbin:

The Class 15 is about the size of an American nickel. Its diameter measures approximately 20.3 mm and has a width of approximately 11.7 mm. This bobbin has two flat sides and is available in both plastic and metal.

This type of bobbin is used by most sewing machines. If you machine makes regular sewing and also you can do computerized embroidery is very probable that your machine use this type of bobbin. We recommend to check your sewing machine manual. This bobbin has the same diameter like size L but a little taller (0.450”)

The L Style Bobbin:

This is the most common embroidery bobbin for commercial and home base embroidery machine. Machines like brother PR-600, Tajima, Melco, Barudan, SWF, Ricoma and Toyota are some of the machines that use Bobbins size L. 

The L Style is about the size of an American nickel. Its diameter measures approximately 20.3 mm and has a width of approximately 8.9 mm. This bobbin has two flat sides and is available in aluminum, plastic, and as a Magna-glide core.

It’s worth noting that the L Style bobbins are the same diameter as the Class 15 bobbins. As such, you can use L Style bobbins in a sewing machine that uses Class 15 bobbins. However, a Class 15 bobbin is too wide to fit in a machine that uses L Style bobbins.

The M Style Bobbin:

This is the most rare embroidery Prewound bobbin. Normally this type of bobbin is used by big industrial embroidery machines (4 heads to 24 heads). The difference between size L and size M is that size M is double size of size L. 

The M Style is about the size of an American quarter. Its diameter measures approximately 24.9 mm and has a width of approximately 10.7 mm. This bobbin has two flat sides and is available in metal, and as a Magna-glide core.