Originally Posted by
amcatanzaro
It's the wrong size 15 bobbin. I'm sure someone has a better explanation than I but the multi holed ones don't fit in a Singer 15, only in Japanese 15's.
If that were true Singer would've had to sell a whole different bobbin for their 15 class machines. I don't personally own a 15-91 but I have friends that do and as long as it's a good quality 15 class bobbin it will work. The problem is finding a good quality bobbin any more. I used to buy them from Sew Classic back when she tested her bobbins for fit. She doesn't do that any more. Thankfully I've got plenty. My best suggestion is to check Ebay and thrift stores for vintage bobbins or buy new plastic ones, they'll work.
Cari