Thread the bobbin before you insert it

A bobbin is the small spool that holds the lower thread in your sewing machine. Before you put it in the machine, you need to wind thread onto it and thread it through the bobbin case. Most machines come with empty bobbins and a bobbin winder — a device on the machine itself that wraps thread around the bobbin evenly.

To wind a bobbin, place an empty bobbin on the bobbin winder post (usually on top of the machine or to the side). Pull thread from your upper thread spool and wrap it around the bobbin a few times by hand to anchor it. Then press the foot pedal or press a button — depending on your machine — and the winder will spin the bobbin and wrap thread onto it automatically. Stop when the bobbin is full but not overstuffed; thread should cover the bobbin evenly without bulging.

Once the bobbin is wound, remove it from the winder. Now you need to thread it through the bobbin case — the small metal or plastic housing that holds the bobbin inside the machine. Open the bobbin case (usually by unlatching a small lever or sliding a cover) and insert the bobbin so the thread unwinds in the direction your machine manual shows. Pull the thread into the tension slot — a small notch in the bobbin case — until you hear or feel a click.

Key Takeaways

  • Wind thread onto an empty bobbin using your machine's bobbin winder until the bobbin is full but not bulging.
  • Open the bobbin case by unlatching the lever or sliding the cover, then insert the wound bobbin with the thread facing the correct direction.
  • Pull the bobbin thread into the tension slot on the bobbin case until it clicks into place.
  • Insert the bobbin case back into the machine and close the cover, making sure it latches fully.
  • Pull up the upper thread to bring the bobbin thread to the surface before you start sewing.

Insert the bobbin case into the machine

Once the bobbin is threaded through the case, you are ready to put it back into the machine. The bobbin case slides into a slot underneath the needle plate — the flat metal surface where the needle goes through the fabric. On most machines, this slot is on the left or right side of the needle.

Slide the bobbin case into the slot until it clicks or latches. You should hear or feel it lock into place. If it does not click, pull it out and try again — a loose bobbin case will cause thread tension problems and skipped stitches. Close the cover or door over the bobbin area if your machine has one.

Bring the bobbin thread to the surface

Before you start sewing, you need to bring the bobbin thread up through the needle plate so both threads are on top of the fabric. Hold the upper thread (the one coming from the needle) gently with one hand. Turn the handwheel (the large wheel on the right side of the machine) toward you one full rotation. This makes the needle go down and come back up, which pulls a loop of bobbin thread to the surface.

When the needle comes back up, you should see a loop of thread on top of the needle plate. Use a small tool like a seam ripper or tweezers to pull this loop up and out. Now you have both the upper thread and the bobbin thread on the surface, and you are ready to sew.

Check your thread tension if stitches look uneven

If your first stitches look loose on top or bunched underneath, the bobbin thread tension may be wrong. This usually means the bobbin thread did not seat properly in the tension slot of the bobbin case. Remove the bobbin case, check that the thread is fully in the slot, and reinsert it.

If the thread is in the slot and stitches still look wrong, check your upper thread tension using your machine's tension dial. Most machines have a numbered dial (usually 0 to 9) on the front. Start at the middle number and test on scrap fabric. If stitches are loose on top, turn the dial to a higher number. If they are bunched underneath, turn it lower. Make small adjustments — usually one number at a time — until stitches look even on both sides.

Know the difference between metal and plastic bobbins

Some machines use metal bobbins and others use plastic ones. Metal bobbins are more durable and hold thread more evenly, but they cost more to replace. Plastic bobbins are cheaper and work fine for most sewing, but they wear out faster and can warp if exposed to heat.

Always use the bobbin type your machine manual specifies. Using the wrong type can cause tension problems or damage the bobbin case. If you are not sure which type your machine takes, check the manual or look at the bobbin that came with the machine. When you buy replacement bobbins, match the brand and type exactly.

Wind multiple bobbins so you do not run out mid-project

If you are working on a large project or using a lot of one color, wind several bobbins before you start sewing. This way you can swap out an empty bobbin without stopping your work. Keep wound bobbins in a small container or bag so they do not unravel.

When a bobbin runs out of thread while you are sewing, stop the machine, remove the empty bobbin from the case, and insert a full one. You do not need to rethread the upper thread — just make sure the new bobbin is threaded through the tension slot the same way as the last one.

Frequently Asked Questions

What happens if I put the bobbin in backwards?

The thread will not unwind properly, and you will either get no thread or very loose stitches. The machine may also jam. Remove the bobbin case and check that the thread unwinds in the direction your manual shows — usually clockwise when you look at the bobbin from the front.

Can I use a bobbin from a different sewing machine?

Not always. Bobbins come in different sizes and styles, and using the wrong one can cause tension problems or damage the bobbin case. Check your machine manual to see which bobbin type it takes, and buy replacements that match exactly.

How full should a bobbin be before I use it?

The bobbin should be full enough that thread covers it evenly, but not so full that it bulges or looks overstuffed. If thread is piled unevenly or sticks out past the edge of the bobbin, it will not wind smoothly through the tension slot. Most machines have a line on the bobbin winder showing where to stop.

Why is my bobbin thread breaking while I sew?

This usually means the bobbin is wound too tightly, the thread is not seated in the tension slot, or the bobbin case is damaged. Try rewinding the bobbin more loosely, check that the thread is fully in the tension slot, and inspect the bobbin case for dents or scratches. If the case is damaged, you may need to replace it.

Do I need to rethread the bobbin every time I change fabric colors?

No. You only need to rethread the bobbin if it runs out of thread or if you want to change the bobbin thread color. If the bobbin still has thread and you are just changing the upper thread color, you can leave the bobbin in place and only rethread the upper thread.