Do you know the difference between 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.
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.