SINGER Class 15 transparent bobbins
Our verdict:
Best spare Class 15 bobbins
Best for machines whose manual lists Class 15 bobbins.
View at SINGERKeep in mind: confirm the bobbin class in your manual first; near-fits cause jams.
Sewing Machines
3 Sewing Machine Bobbin Picks by Type and How to Choose the Right One in 2026
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.
What's covered8
- #1. SINGER Class 15 bobbins: best spare Class 15 bobbins
- #2. Brother SA156 bobbins: best for Brother drop-in machines
- #3. Simthread prewound bobbins: best prewound bobbins for embroidery
- Factors to consider when choosing a sewing machine bobbin
- Metal or plastic bobbin?
- Prewound bobbins
- Bobbin tips that prevent problems
- Where to buy the bobbin you need
Our top 3 picks
- 1Best spare Class 15 bobbinsSINGER Class 15 transparent bobbinsView at SINGERRead our analysis
- 2Best for Brother drop-in machines
Brother SA156 bobbins, 10-packView at BrotherRead our analysis - 3Best prewound bobbins for embroidery
Simthread prewound bobbins, size A (SA156), 144-packView at SimthreadRead our analysis
A 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.
#1. SINGER Class 15 bobbins: best spare Class 15 bobbins
A cracked or near-fit bobbin causes loops and jams, plus tension trouble. Spare transparent Class 15 bobbins are useful only when your machine takes that exact class. Check the manual and the current package count before buying. See sewing machine bobbins for other types.
#2. Brother SA156 bobbins: best for Brother drop-in machines
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 at BrotherKeep in mind: check your manual first; not every Brother model uses SA156.
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.
#3. Simthread prewound bobbins: best prewound bobbins for embroidery
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 at SimthreadKeep in mind: white only, and fine embroidery-weight thread; wind your own bobbins for colored garment seams.
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.
Factors to consider when choosing a sewing machine bobbin
| 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.
Metal or plastic bobbin?
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
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.
Bobbin tips that prevent problems
- Wind bobbins at an even, moderate speed so the thread lies smoothly.
- Never add thread on top of a partly wound bobbin.
- Throw away bobbins with cracks, nicks or bent sides.
- Keep bobbins in a case so they do not collect lint or get bent.
Where to buy the bobbin you need
If stitches look loose underneath or the thread tangles, see bobbin tension on a sewing machine and sewing machine bobbin jamming. For help choosing a machine, compare the sewing machine picks.
FAQ
Are all sewing machine bobbins the same?
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.
Can I use metal bobbins in a machine that came with plastic ones?
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.
Are prewound bobbins worth it?
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.