Yes, you need a bobbin to sew on any machine that uses one — but not all machines do
A bobbin is a small spool that holds the bottom thread on a sewing machine. Most home sewing machines require one. The bobbin sits in a case beneath the needle plate and feeds thread upward to lock with the top thread and form a stitch. Without a bobbin, the machine cannot complete a stitch at all.
However, some machines work differently. Sergers (overlock machines) use a different threading system and do not have bobbins. A few specialty machines also skip them. If your machine came with bobbins in the box or has a bobbin case visible under the needle plate, you need one to sew.
The bobbin itself is reusable — you wind it with thread, insert it into the machine, and use it until the thread runs out. Then you wind it again. Most sewers keep several bobbins on hand so they can switch thread colors without rewinding.
Key Takeaways
- Standard home sewing machines require a bobbin to form stitches; the bobbin holds the bottom thread while the top thread locks with it.
- Bobbins are reusable spools you wind yourself using your machine's bobbin winder, which comes built into most machines.
- Different machine types use different bobbin sizes and styles, so you must match the bobbin to your specific machine model.
- Keeping three to five wound bobbins in common thread colors saves time when switching between projects.
How bobbins work in a stitch
When you sew, two threads meet at the needle. The top thread comes from the spool on top of the machine and passes through the needle. The bottom thread comes from the bobbin below. As the needle moves up and down, it loops the top thread around the bobbin thread, and the two lock together to form a stitch.
If the bobbin is empty, missing, or inserted incorrectly, the machine cannot complete this loop. You will see broken stitches, loose loops, or the machine will not sew at all. The bobbin must have enough thread on it to complete your project — if it runs out mid-seam, you have to stop, rewind, and start again.
Types of bobbins and how to match yours
Bobbins come in different sizes and styles depending on your machine. The three most common types are Class 15 (metal, used on older and some modern machines), Class A (plastic, very common on home machines), and Class L (larger plastic, used on some newer models). Using the wrong bobbin size can cause tension problems or prevent the bobbin case from closing.
Check your machine's manual or look at the bobbin case itself — most have the correct bobbin type printed on them. If you have lost the manual, search your machine's model number online or take a photo of the bobbin case to a fabric store. Staff can usually identify the right type in seconds. Buying the wrong bobbin wastes money and time.
Metal bobbins last longer than plastic ones and hold slightly more thread, but they cost more. Plastic bobbins are cheaper and work fine for most sewing. Many machines come with one or two bobbins; buying a set of five to ten of the correct type is a practical investment.
How to wind a bobbin
Your machine has a bobbin winder — a small mechanism, usually on the side or top of the machine, that spins the bobbin and winds thread onto it. To wind a bobbin, place an empty bobbin on the winder spindle, thread the bobbin winder following your manual's diagram, and press the foot pedal or press a button (depending on your machine). The winder automatically stops when the bobbin is full.
Wind bobbins before you start sewing, not during a project. Most machines wind a bobbin in two to three minutes. Use the same thread color as your top thread unless you are doing decorative work where the bobbin thread shows on purpose. Winding with cheap or old thread can cause it to break mid-stitch, so use decent quality thread for bobbins.
What happens if you run out of bobbin thread mid-project
If your bobbin runs out while you are sewing, stop when ready and do not sew backward. Cut the thread, remove the fabric, and rewind or replace the bobbin. Then rethread the machine (both top and bobbin), position your fabric where you left off, and lower the presser foot before sewing again. Sewing without a full bobbin will cause loose, weak stitches that can unravel.
To avoid this, wind bobbins with enough thread for the project you are starting. A full bobbin usually holds enough thread for several seams on a garment, but large projects like quilts or heavy fabric may need two or three bobbins. If you are unsure, wind an extra one — it takes only a few minutes.
Machines that do not use bobbins
Sergers and overlock machines use a different stitch formation and do not have bobbins. Instead, they use multiple spools of thread that feed directly into the machine. Some specialty machines like embroidery-only machines or industrial coverstitch machines also skip bobbins. If you own one of these machines, you do not need to wind anything — thread straightforward feeds from the spool.
If you are shopping for your first machine and want to avoid bobbin winding, sergers are an option, but they are more expensive and are designed for finishing seams rather than basic sewing. For general sewing, a standard machine with bobbins is the most affordable and versatile choice.
Storing and organizing bobbins
Keep wound bobbins in a small container or bobbin case so they do not unwind or get lost. Label them with the thread color using a permanent marker or small sticker. Store them in a cool, dry place away from direct sunlight, which can fade thread. Most sewers keep bobbins wound in their most-used colors — black, white, navy, and neutral tones — so they are ready to use without winding.
If you sew regularly, having five to ten bobbins wound saves time and frustration. You can switch colors without stopping to wind, and if one breaks or runs out, you have a backup. Over time, plastic bobbins can crack or wear, so replace them if you notice damage.
Frequently Asked Questions
Can I sew without winding a bobbin first?
No. The bobbin must be wound with thread before you insert it into the machine. An empty bobbin will not form stitches. Winding takes only a few minutes and is a necessary step before every project or color change.
What if I put the bobbin in upside down or backward?
The machine will not sew properly or will not sew at all. Most bobbin cases have a slot or mark showing the correct direction. Check your manual for the correct orientation, and if stitches are loose or broken, remove the bobbin, rewind it if needed, and reinsert it the right way.
Do I have to use the exact bobbin my machine came with?
You must use the correct bobbin type for your machine, but you do not have to use the original one that came in the box. Any bobbin of the same class and size will work. Replacement bobbins are inexpensive and widely available at fabric stores and online.
Can I use a bobbin from a different brand machine?
Only if the bobbin type matches. A Class A bobbin from one brand will work in another brand's machine if both use Class A bobbins. Check the bobbin case or manual to confirm the class, and test it before starting a project to make sure it fits and winds correctly.
How do I know when a bobbin is full?
Most bobbin winders have a sensor that stops automatically when the bobbin is full. If your machine does not have an automatic stop, the bobbin is full when thread is wound evenly to the edges and feels firm to the touch. Overfilled bobbins can jam; underfilled ones run out quickly.