Originally Posted by
Macybaby
the metal bobbin with the holes is for the high speed industrial, and if you are sewing fast it really helps to keep the bobbin cooler having the holes.
My Bernina 630,440, and 215 all came with metal bobbins with holes in the sides. I was told never to use any other bobbins for my machines. I think the best thing to do, is to use the bobbins that came with your machine, and if you need more, buy them for your specific machine. I have never used the generic type bobbins sold by chain stores. Sure, they may cost more, but I figure I same money and time. That said, it is possible you could get a warped bobbin or even create a warped one by dropping it on the floor.