Sewing Machines
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The short answer
Use only the bobbin type your manual names. Bobbins that look the same can differ slightly in height, width or material, and a near-fit bobbin causes tension trouble and jams.
SINGER Class 15 transparent bobbins, 50-pack
Brother SA156 bobbins, 10-pack
Simthread prewound bobbins, size A (SA156), 144-packA bobbin is the small spool that holds the lower thread in a sewing machine. The bobbin thread locks with the top thread to form every stitch. So the bobbin, small as it is, affects your stitches as much as the needle does. This guide starts with three bobbin picks for the most common bobbin style. Then it covers bobbin types and sizes, and how to pick the right bobbin for your machine.
SINGER Class 15 transparent bobbins, 50-pack
Our verdict:
Best spare Class 15 bobbins
Best for machines whose manual lists Class 15 bobbins.
View on AmazonKeep in mind: confirm the bobbin class in your manual first; near-fits cause jams.
Product details checked September 2026
Buy bobbins made for your brand and model, or a pack clearly labeled for your bobbin class. Many SINGER home machines take Class 15. For those, a spare set of SINGER Class 15 clear bobbins is an easy backup. Always check the class in your manual first.
Brother SA156 bobbins, 10-pack
Our verdict:
Best for Brother drop-in machines
Best for Brother machines that take SA156 bobbins, as spares for each thread color.
View on AmazonKeep in mind: check your manual first; not every Brother model uses SA156.
Product details checked September 2026
Brother calls its Class 15 size bobbin SA156. This 10-pack is Brother's own clear plastic version, made for its sewing and embroidery machines. The clear sides show when thread runs low. Spare bobbins let you keep a few colors wound and ready. Check your manual before you buy, since not every Brother model takes SA156.
Simthread prewound bobbins, size A (SA156), 144-pack
Our verdict:
Best prewound bobbins for embroidery
Best for machine embroidery and long quilting sessions where bobbin changes slow you down.
View on AmazonKeep in mind: white only, and fine embroidery-weight thread; wind your own bobbins for colored garment seams.
Product details checked September 2026
If you do machine embroidery or long quilting sessions, prewound bobbins cut down on winding. This pack holds 144 size A (SA156) bobbins filled with fine white polyester thread. The maker lists the machine brands they fit in the product description. For colored garment seams, wind your own bobbins with thread that matches the top thread.
| Bobbin style | Where you find it | Notes |
|---|---|---|
| Class 15 (also called A style) | Many home machines from SINGER, Brother, Janome and others | Comes in metal and plastic; Brother lists its version as SA156 |
| Class 66 | Some older SINGER models | Slightly curved sides; not the same as Class 15 |
| L style | Many longarm, embroidery and some industrial machines | Wider than Class 15 |
| M style | Larger industrial and longarm machines | Holds much more thread |
| Brand-specific | Some BERNINA, PFAFF and HUSQVARNA VIKING models | Use the maker's own bobbin |
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Bobbins that look alike can differ by a fraction of a millimeter. A bobbin that "almost fits" can wobble, leave loops under the fabric or jam. The model number and the manual are the only safe guide.
Use whatever your manual says. As a rule, top drop-in bobbin systems are often made for plastic bobbins. Front-loading bobbin cases often take metal ones. Mixing them can change the bobbin tension. Clear plastic bobbins have one small plus: you can see how much thread is left.
Prewound bobbins come filled with thread. It is often a fine, strong thread, so it holds more length than a bobbin you wind yourself. Quilters and embroiderers use them to change bobbins less often.
They come in the common styles above. Some have plastic or card sides, and some have no sides. Check that your manual allows the style before you use them.
If stitches look loose underneath or the thread tangles, see bobbin tension on a sewing machine and sewing machine bobbin jamming. For machine buying guides, go back to the sewing machines hub.
No. They come in different classes and styles, in metal or plastic, and each machine is designed for one type. Check the manual or the maker's website for your model.
Only if the manual allows it. Many top drop-in bobbin systems are designed for plastic bobbins, and a metal bobbin can change the tension or damage the holder.
They save time on large projects and machine quilting, and they hold a lot of thread. Make sure the style matches your machine, and check the manual before using sideless prewound bobbins.
