Bobbins

Did you know there are over 60 different bobbins styles. Some are very similar and some are dramatically different. Lets take a look at some of the  most popular bobbins

Class 15 ( A Style):

The Class 15 A 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.

Class 15 ( J Style):

The Class 15 J diameter measures approximately 20.4mm and has a width of 11.3 mm. This bobbin is only available in plastic. The bobbin looks very similar to the Class 15 A style bobbin however, there is a slight curve to the sides. Even though the curve is barely visible, it is still significant enough to affect performance (eg: bobbin not winding fully or bobbin bouncing in bobbin case) and is not recommended to  be used in a Class 15 A Style machine.

Class 66 :

The Class 66 diameter measures approximately 20.5 mm and has a width of approximately 10.9 mm. This bobbin is available in metal or plastic. This bobbin is significantly curved on both sides . Even though the bobbin appears to be similar to the Class 15 Bobbins, it will affect the performance of your machine and should not be used in Class 15 Machines. 

L- Style:

The L- Style diameter is approximately 20.3,mm and has a width of approximately 8.9 mm. The bobbin as two flat sides and is available in plastic, aluminium and Magna-glide core. The L-Style bobbin and Class 15A have the same diameter and therefore will fit Class 15A machines, however Class 15A is too wide for for L-Style machines. Most pre-wound bobbins are L-Style bobbins.