Sewing machine skipping stitches: 7 causes and solutions

Few things are as frustrating in sewing as being halfway through a project and the machine starts "skipping" stitches, leaving loose loops, or constantly breaking the thread. If this is happening to you, don't despair and (above all) don't immediately mess with the bobbin case screws.

In the vast majority of cases, the problem is not a serious mechanical breakdown, but rather a small detail of maintenance, material choice, or incompatible parts. With almost a century of experience in the sector – Moura & Fortes has existed since 1928 – our technical team has gathered the 7 most common causes for a sewing machine to skip stitches and their respective solutions.

1. The needle is worn or generic (low quality)

The number one cause for skipping stitches and breaking threads is the needle. Needles undergo enormous wear (they enter the fabric dozens of times per second). After about 8 hours of sewing, the tip starts to become blunt or the needle bends slightly (even if not visible to the naked eye), preventing the bobbin case from catching the thread at the exact moment.

Furthermore, avoid generic, white-label, or questionable quality needles as much as possible. Often, these needles have finishing defects and micro-burrs in the eye, which cut or fray the thread during sewing. The golden rule is simple: choose quality needles, like those from SCHMETZ. The investment is minimal, but it translates into fewer failures, fewer thread breaks, and greater stitch consistency.

2. You are using the wrong needle for the type of fabric

Even a new needle from the best brand will skip stitches if it's the wrong needle for the fabric you have under the presser foot.

The most classic example is trying to sew knits, lycras, or elastic fabrics (like t-shirts) with a Universal needle. The sharp point of this needle cannot penetrate the knit correctly to form the loop underneath. The solution is simple: switch to a Stretch or Jersey (Ballpoint) needle and watch the problem disappear instantly.

3. The needle was inserted incorrectly into the machine

If you have just changed the needle and the machine started skipping stitches, it is most likely that the needle was inserted incorrectly. In most domestic sewing machines (SINGER, PFAFF, Husqvarna Viking), the flat part of the needle shank must face backwards.

Another common mistake is not pushing the needle all the way to the top of the clamp before tightening the screw. If the needle is a millimeter lower than it should be, it will be "out of time" with the machine and the bobbin case will pass over or under the thread, missing the stitch.

4. The machine is incorrectly threaded or the bobbin is wrong

If the upper thread jumped out of the take-up lever or did not pass correctly between the tension discs, the loop will not form with the necessary consistency. The quick solution is to remove all threads (the upper and the bobbin thread), ALWAYS raise the presser foot to open the tension discs, and rethread the machine from scratch.

Another extremely frequent problem is the use of wrong bobbins. To the naked eye, many bobbins look the same, but they have different heights or curvatures. Using a plastic or metal bobbin that is not specified for your brand and model changes the clearance in the bobbin case, causing skipped stitches, loose loops, or jams. Use only bobbins compatible with your model.

5. Poor quality threads and their impact on lubrication

Excessively cheap threads or those bought in non-specialized stores are often composed of short fibers that generate a lot of dust and lint, not having a regular thickness along the thread. When a thicker part of the thread passes through the needle or the tension discs, it slightly snags, which prevents the correct formation of the loop and causes the stitch to fail or the thread to break.

But the problem doesn't stop there: this excess lint quickly accumulates inside the machine, especially in the bobbin area, and ends up absorbing the lubricating oil. With dry mechanical parts and inadequate lubrication, friction increases, which not only impairs sewing but also drastically reduces the lifespan of your equipment.

Always use good quality sewing threads (such as Madeira brand polyester). Branded threads offer consistent tension, do not fade, and keep the interior of your machine clean and lubricated for much longer.

6. The thread tension is completely out of adjustment

Often, what appears to be a "skipped stitch" is actually a tension problem. If the upper tension is too loose, the thread will create loose loops and tangle on the underside of the fabric. On the other hand, if the upper tension is at maximum (too tight), the machine will pull the fabric excessively, the stitch will look aesthetically displeasing, and the thread will eventually break under the strain.

The solution is to make it a habit to always test. Before moving on to your final piece, perform tests on a double scrap of the same fabric you will be sewing. Set the tension to the intermediate position (usually between 3 and 5) and make small adjustments until the stitch is smooth and balanced on both sides.

7. Damaged bobbin case/needle plate or out-of-tune machine

You've changed the needle, rethreaded the machine, checked the bobbin and tension, and used good threads, but stitches are still skipping? The problem might be physical.

If you recently broke a needle (for example, by sewing over a pin or through very thick fabric), the needle tip might have hit the metal of the machine. This creates small "nicks" and sharp burrs on the needle plate or the bobbin hook. The upper thread catches on these burrs as it goes down and breaks or skips the stitch. Additionally, excessive lint accumulation in the bobbin case area also prevents smooth thread passage.

If, after cleaning, the machine continues to malfunction, it is very likely that the bobbin case is nicked or that the machine has "gone out of time" (mechanical discoordination). In this case, do not try to force it or loosen internal screws.

Moura & Fortes, a store distinguished with the "Porto de Tradição" seal, has a specialized technical team. Bring your machine to our stores and workshops in Porto or Lisbon, where our sewing machine technical assistance service will replace damaged parts, adjust the "timing", and synchronize the equipment so you can sew perfectly again.

Frequently Asked Questions (FAQ)

Why does the sewing machine skip stitches only on knit fabric?

Knit and elastic fabrics (like jersey or lycra) require specific needles with a ball point (Ballpoint or Stretch). If you use a universal needle, the overly sharp point pierces and pushes the fabric thread instead of sliding between the weave, preventing the loop from forming in the bobbin case.

The machine skips stitches and breaks the thread: what's the connection?

Normally, if the machine is skipping stitches and breaking the thread successively, the problem lies in the quality of the needle/thread or in metallic burrs. Generic needles may have a poorly polished "eye", and a nicked needle plate has sharp edges that act like blades, cutting the thread with each descent.

Can I use any bobbin in my machine?

No. Using a plastic or metal bobbin that is not specific to your brand and model will alter the lower thread tension. This causes loose loops, skipped stitches, and even mechanical jams in the bobbin area.