Originally Posted by Tink's Mom
Please use whichever type of bobbin that originally came with your machine....if it is plastic...stick with it...even if the metal fits.
You can cause damage to your bobbin case with the wrong kind.
Yes!! Vintage machines and machines with metal cases were engineered and manufactured to take metal bobbins. Newer machines with plastic bobbin cases are engineered and spec'd for plastic. Just because it fits, doesn't mean you should use it.