Bobbins are those tiny elements that fit into a sewing and embroidery machine that holds
the thread to stitch the fabric, or the design onto the fabric. While these bobbins are a very
important constituent of a machine, they are almost always forgotten about. Both sewing
and embroidery machine bobbins are different, you may know that already. But, do you
know that in all, there are more than 60 different bobbin styles available!? While some are
quite different, there are others that are so similar, that it is difficult to see any difference at
all. We won't be speaking about all 60 of those bobbins, but let us take a look at some of the
most commonly used bobbins.
Class 15 (A Style) Bobbin
Class 15 or Style A bobbin is about the size of an American nickel, with a diameter
approximately 20.3 mm and width approximately 11.7 mm. It has two flat sides, and is
available in both metal and plastic.
Class 15J Bobbin
Another bobbin that is about the size of an American nickel, the Class 15J bobbin has a
diameter of approximately 20.4 mm and width approximately 11.3 mm. But, this bobbin is
available only in plastic. While it looks similar to a Class 15 bobbin, it has a slight curve to
its sides. This curve is barely visible, but it can significantly affect the performance of the
bobbin. Thus, Class 15J bobbins cannot replace Class 15 bobbins in a machine.
Class 66 Bobbin
Class 66 bobbin is yet another bobbin that is about the size of an American nickel. It has a
diameter of approximately 20.5 mm and a width of approximately 10.9 mm. It is available
in both metal and plastic. It has a significant curve on the sides, and appears to be same as
the Class 15 bobbin; however, it cannot replace the bobbin in any machine.
L Style Bobbin
Style L bobbin is the size of an American nickel, measuring approximately 20.3 mm in
diameter and approximately 8.9 mm in width. It has two flat sides, and is available in
plastic, aluminum, and Magna-glide core.
M Style Bobbin
Style M bobbins are about the size of an American quarter, with a diameter of
approximately 24.9 mm and width of approximately 10.7 mm. It has two flat sides, and is
available in metal and Magna-glide core.
Now that we know about the most common bobbins that are used depending upon the
structure and size, let us look at some others that are classified based on the material they
are made of. While there is a list of materials that bobbins can be made of, the most
common ones include metal, aluminum, and plastic.
Metal bobbins – These are the most common bobbins used, made of treated steel. These are
often preferred over aluminum and plastic bobbins.
Plastic bobbins – These bobbins are becoming more popular as they are durable and
inexpensive, and they generally perform just as well as metal bobbins.
Aluminum bobbins – These bobbins are light in weight and spin faster than metal and
plastic bobbins. They perform better than metal and plastic bobbins, but can easily be
scratched and damaged.
One other important thing to note here is that bobbins are often confused with pirn. But,
both bobbins and pirns differ a great deal. Pirns are rods that taper at the sides, and are not
wound evenly from end to end like bobbins. Thus, while they perform similar in fashion to
bobbins, they are actually quite different. But, whatever your requirement, you can get
them all at Trim Engineering Services, the leading bobbin and pirn manufacturers in