Sewing Machine Tension Problems | 7 Common Issues

When sewing, your thread tension is the most important thing that you need to be aware of.

Problems with your thread tension can cause issues with sewing your projects. Thread tension could either be too loose or too tight.

So what happens when there are problems with your thread tension?

What Typically Happens When the Tension is Too HIGH?

There are a few issues that you can have if your thread tension is too high:

1. Seam Puckering:

One potential issue with thread tension that is too high is seam puckering.

Seam puckering can be caused by tension that is too tight on a light-weight fabric.

You also might need to adjust your stitch length if the puckering continues after you fix your thread tension.

2. Seam Breaking:

If your tension is too tight, you could also have your seam break.

If both your bobbin tension and top thread tension is too tight, your seam could break easily if you stretch them.

This is not ideal for any project, but especially not those that are intended to be worn.

3. Thread Breaking:

Depending on what type of thread you are using, you will need to adjust your tension to match.

If you are using a thread that is lighter or heavier than you usually use, you will have to adjust your tension. If your tension is too tight, your thread could break while you are sewing.

This will cause you to have to continuously start and stop in the middle of your seams which can make them look sloppy and uneven.

4. Bobbin Won’t Unwind:

If your bobbin tension is too tight, you could get unnecessary pressure put on the thread as it goes through the bobbin case.

If this happens the bobbin thread will be prevented from unwinding freely.

This is a common problem with heavier or thicker threads being used than your tension is normally set for.

5. Uneven Tension:

If you have your top thread or bottom thread set to a tension that is too high, it could cause uneven tension.

Uneven tension is when your bobbin thread and top thread are not set to the same tension.

When this happens you can get visible knots or loops in your stitches. When the bobbin thread shows on the right side, the needle tension is too tight.

If the needle thread shows on the wrong side, the bobbin tension is too tight.

How Did This Happen?

Thread tension that is too high usually comes from the top thread instead of the bobbin, but this is not always the case.

If it is a problem with your top thread, it could be coming from your tension dials or your thread is getting stuck somewhere.

If it is a problem with your bobbin thread, it is because the screw on your bobbin case is set to be too tight.

What Typically Happens When the Tension is Too LOW?

6. Uneven Tension:

Just like when your thread tension is too high, if your thread’s tension is too loose, you could have uneven tension.

In this case: When the needle thread shows on the wrong side, the needle tension is too loose.

If the bobbin thread shows on the wrong side, the bobbin tension is too loose.

7. Gaps in Your Seam:

If both your top thread and your bobbin thread are set to a tension that is too loose, you could get gaps in your seam.

This will cause your seam to expose the threads between the sections and will not have a clean and closed seam for your project.

Your fabric will also not be held together properly and won’t hold up in the long run.

Bonus! Bobbin Keeps Unwinding:

The bobbin thread also cannot be too loose when you are sewing. If your bobbin thread is set to a tension that is too low, you could get backlash.

Backlash is when your machine is no longer sewing, but your bobbin thread continues to unwind.

This is a problem that occurs when you are using a very smooth or fine thread that your bobbin case is not set to use.

How Did This Happen?

Thread tension that is too low could either come from your top thread or your bobbin thread.

If it is a problem with your top thread, the most common cause of your tension issue is likely coming from your tension dials.

If it is a problem with your bobbin thread, it could be because the screw on your bobbin case is set to be too loose.

Another potential issue is that your bobbin thread was not wound in your bobbin properly.

What is the Correct Tension for My Sewing Machine?

The correct tension for your machine will depend on a number of factors, and there is not a “one-size-fits-all” answer to how much tension you should have.

There are a few things that you need to look at when you are determining what is the right tension to use for your machine:

Thread and Fabric Type:

When looking for what you should set as your tension, you will need to take into account both the fabric choice and the thread choice.

Lighter fabric and thread will require less tension than a piece of heavier fabric or thread. If you do not match your tension with your materials, you will have tension issues.

The best way to know if your thread tension is correct is to use a test strip of fabric before you start on your actual project.

Using a test strip will allow you to test your stitch until the tension is right and your seam is perfect.

Having Even Tension:

Another thing you need to keep in mind when you are setting the tension on your machine is to make sure your tension is even.

This means that you want to make sure that you are setting the tension on the top thread to correspond with the tension on the bobbin thread.

This can vary based on what your bobbin case is set to, tension wise, and will need to be adjusted based on the thread being used.

How Do I Know if I’ve Set the Tension Correctly?

To know if your tension is perfect, you will want to look at your seam on the test strip of fabric.

You will know that your seam is perfect if your stitch looks exactly the same on both sides of your fabric. The stitches will also be evenly spaced apart and your seams will lie flat on the fabric.

You will know that your stitch is wrong if your thread pulls out easily, you have gaps in your stitch, or you have loops of thread or your thread bunches up when sewing.

You shouldn’t be able to see the knot formed between stitches.

What if It is Not a Tension Issue?

You could be having some issues that are similar to tension issues but could be coming from other issues with your machine.

Before you start to mess with your tension settings, you will want to make sure that tension is really what is causing the problem.

First, before you decide anything you will want to sew a test seam on a scrap piece of the fabric that you are using. If you do not have an issue on the test scrap, then you should not adjust your tension.

If you are having a problem with your test strip, then you will want to make sure you find what the issue is.

Possible causes of issues that aren’t tension include:

  • Your machine is threaded incorrectly
  • Your bobbin is not inserted properly
  • Your machine is dirty or there is some obstruction
  • Your machine is damaged in some way.
    • This could include bent needles, damaged bobbins, motor problems, or other damage
  • You are using the wrong type of needle for your fabric.
    • Heavy fabrics like denim will require a thicker needle, but the more thin, delicate fabrics will require a thinner needle so that the fabric is not damaged

If you have ruled out these options, then you are safe to start changing the tension to fix your issues.

How Do You Fix Problems With Bobbin Tension?

Bobbin tension can be one thing you look at when you are looking for tension problems. Most people don’t think to change the tension on the bobbin case.

The average sewer is afraid to make changes to the tension in general but that is especially true when it comes to bobbin tension.

To fix any problems that you come across with bobbin tension, you will want to focus on the bobbin case.

Front-Loading Bobbin:

If you have a front-loading bobbin, to fix the tension, you will want to start by removing the bobbin and its case from your sewing machine.

Ensure that the bobbin thread is threaded through the bobbin case properly. There is also a small screw on the bobbin case that can be adjusted to change the bobbin tension.

When you are making these adjustments, only change the tension slightly. Even the smallest turn can make drastic changes to your bobbin. You will want to turn your screw to the right to tighten and to the left to loosen.

If you have more than one type of thread that you are working with, you can use more than one bobbin case.

That way, you can have each case set to the tension that is needed without having to constantly be changing the tension.

Top-Loading Bobbin:

One issue with the top-loading bobbin case is that you can’t remove the bobbin case from the machine. This means that you also cannot change the tension in the bobbin thread.

This can be a problem for your thread tension because you will have to do all your adjusting with the top thread instead.

This gives you less control over the thread tension because your bobbin tension and top tension must be even so that there is no issue between the two.

How Do You Adjust the Tension on a Sewing Machine?

Having the proper tension for your top thread is not hard, but there are things that you will need to do to ensure proper tension and adjust if necessary.

Some people get nervous when they think about adjusting the tension on the machine. Getting it wrong can be intimidating to people who are not used to changing the tension on their machine.

Changing the tension does not have to be intimidating. Just make sure you test it on a scrap of fabric before you try it on your fabric you intend to use in your project.

This way, you can make sure you have it right before you work on your actual project.

When you thread your machine, there are things that you will want to look out for and adjust in regards to thread tension. These things include:

Thread Guides:

Your thread guides are various metal loops that you run your thread through before you thread it through your needle.

The purpose of these devices is to keep your thread from being tangled and help to distribute the thread’s tension evenly throughout the thread.

Tension Disks/Regulator:

The tension disks and tension regulator squeezes the thread when it goes through them. This allows you to adjust the tension of the top thread to be higher or lower.

When working with the tension regulator, you just have to adjust the number to a higher number to increase the pressure or a lower number for a decrease in pressure. This will change the amount of pressure on the tension disks.

Depending on the age of your machine, it might work differently.

Older machines normally only have two tension disks that you can control with a knob or screw. Newer models usually have three disks that you can control using a keypad or dial on your machine.

Some newer and more sophisticated machines are even able to make automatic tension adjustments. If you don’t have a machine that makes automatic adjustments, you will have to change your tension yourself when you need to.

Using a different type of thread without adjusting your tension accordingly can result in tension issues.

Can Tension Issues Cause Loops on the bottom of the Fabric?

Tension issues can indeed cause loops on the bottom of your fabric. This can be annoying to undo and can create a tangled mess.

Loopin on the underside of the fabric means that the top tension is loose when you compare it to the bobbin tension.

This means that the bobbin thread is pulling too much of the top thread underneath the fabric. To correct this, you will need to adjust the top tension.

If you adjust the top tension by too much you could run the risk of other issues like your thread breaking.

You could also loosen the bobbin tension to match the top tension if you cannot afford to tighten the top tension anymore.

Final Thoughts:

Making sure your tension is correct is important when you are using your sewing machine. Tension problems can lead to all sorts of problems with your fabric, your thread, and can even lead to issues with your machine.

In addition to paying attention to your thread’s tension, you should also take steps to take care of your machine to prevent other potential issues.

This means keeping your machine clean and free of dirt and debris. You will also want to make sure your needle is straight and that you are using the correct one.

Inserting the bobbin correctly, and putting your machine back together properly after cleaning is also very important. If this is not done right, you can have a few different issues.

Another thing that you should do is to regularly get your machine looked at and serviced. Getting your machine looked at by a professional can save you from expensive issues down the line and it can help extend the life of your machine.