I thought we bought one as it was sold to us as such but it definitely is not a 1/4 inch when on the Singer 15-91. How do I obtain a 1/4 inch for piecing? Or do I need to resort to tape? The foot was sold for both a low shaft Singer 66 treadle and an electric low shaft Singer15-91. They are supposed to both use the same feet. Where we told wrong by the seller?

I have a Singer 15-91 It takes a low shank 1/4" foot. I bought it on E-Bay. Hope this helps

I also have a 66 treadle and just bought a 15-91. I'd love to know what you find out. Does this 1/4 inch foot also fit a featherweight??

Featherweight is also a low shank. Don't know about a 66. I love my 15-91. It will sew when everything else fails. I have a treadle but have not used it in many years. Learned to sew on one when I was a kid. But use my Janome4800QC and Singer 403 now. 403 is a slant shank with zz stitch but I still like the 15-91 better. The feeddogs will drop for FM and it is heavy so it doesn't travel when you sew on it.Have you checked the vintage Singer groups on Yahoo? They have information on all the vintage Singers. They have been a big help to me over the years with my vintage Singers. Hope you have good luck.

Note: 15-91 needle goes in with flat side to left and threads from right to left. After using my other machines I tend to forget this when I change the needle. Doesn't take long to figure out something is not right. But I do it everytime. Hope I haven't stated the obvious. It definitely is not obvious to me or I wouldn't do it every time I change the needle.lol

My apology to our resident vintage machine guy. I am new and didn't realize there was one on this board or I would have referred you to him. I hope I did not offend you Billy. I wish I had found you earlier when my 403A tensiion was giving me fits.