A different batch. The quality control with these bobbins (coming from China) is lousy.

ditto on that:)

The local Walmart here doesn't even sell class 15 bobbins anymore. No tag for them or anything, only class 66 in plastic (ugh) or metal.

I do have a class 15 bobbin that came with one of my featherweights ?!?! I keep it around to show people why not to buy cheap bobbins. It doesn't even fit into a class 15 bobbin case. If you really shove it does ( one guy did that, then I had to show him why -that- was a bad idea....)

Other than the vintage ones I have from various machines, I've only ever bought new ones from Sew-Classic, or one 10 pack from a regular seller on Ebay (terry something... I can't recall exactly). I have no FW bobbins here that don't work, so I'd second (third?) that Jenny's are good bobbins.

One reason that the foreign made ( not just Chinese ) bobbins don't always work in our older machines is because of the dissimilarity of the measuring systems. Some times foreign makers do not use the inch measurements, they just convert it to metric and go from there. What they do a lot of the time is round up to the next largest MM and that is what throws the specs off.
If the inch measurement converts to 11.5 mm, they round it up to 12.0 mm and then it's too big.

Tammi,

There is nothing wrong with an in-spec plastic bobbin except it's plastic. My wife has been using them interchangeably with the metal ones since she got her Singer 538 back in '78. Nary a problem.

I've used them in Singer 66s made back in the 19 teens with no troubles either. The only plastic bobbin I had that didn't work was one that got dropped on the floor and stepped on. KArunch ..... :(



Joe

LOL! Yeah, I can see how that one wouldn't work. :) I just find that they seem to jump around a little more, and although I know it can't be true, in fact should be the opposite - it seems sometimes that they're louder. I seem to end up with a lot of cracked (older) ones too.

I was once told by an OSMG that if the case is plastic, use a plastic bobbin. If it's a metal bobbin case, use metal.

I was also told by another one that he only used plastic, because the metal ones could get magnetized and mess with tension and your mind as a result. I drop my bobbins enough, I don't think they can keep any magnetization they might develop. :) Just call me "fumble".

It's all over the map. I had one OSMG say use the plastic when you want to sew fast. LOL
SSSSOOOOOOO what if they do get magnetized? I just know some bobbins are better than others.

Its hit and miss with the JoAnn's FW and other bobbins for our old machines. I bought some and the bobbin got stuck in my bobbin case. I only use vintage original bobbins whenever possible now.
Sharon

The rule of thumb I've also read is: Plastic bobbins for plastic bobbin cases and metal for metal. My wife didn't know the metal ones would or could cause more wear to the plastic bobbin case so she just used 'em.

I have some metal Class 66 bobbins that are significantly narrower between the rims than the proper size bobbins. They do cause tension problems on some of my machines and they rattle as they vibrate up and down. Some of the plastic bobbins I have are a bit narrower between the rims too. So I suspect they do the same.
I'm in the process of weeding out any bobbins that do not match the original Singer sizes. I won't bin them, but I'll not use them either.

Joe

Aw Joe are you going to make some earrings???

I think OSMGs might have as many myths as the rest of us that they propagate. He'd said to me that a magnetized bobbin tended to "stick" and loosen, causing inconsistent tension. I'm not sure I believe that.

I wonder if that's why I've heard that they wear bobbin cases out and replace them "once a year" from a few people with "modern" brother machines who sew a lot. And I mean a LOT. It seemed strange to me, but if they're using metal bobbins and a plastic case, maybe?