Recently updated on April 5th, 2023
The following have probably happened to you: skipped stitches, broken thread, puckered fabric, or thread nests on the back of your fabric. The root cause of all of these problems is thread tension, no matter how diverse they may appear. What is the best way to adjust the tension on a sewing machine? You can save a lot of aggravation by doing this.
What is Sewing Machine Tension?
Two threads run through your sewing machine: the top and bobbin threads. A chain is formed when these two threads are interlocked by the sewing machine.
Each thread is kept taut by your sewing machine while it pulls it through. The result is tight, even, consistent stitches formed by them working together. It can cause problems with your stitching if either thread is not tensioned correctly.
The top thread usually causes tension problems, but not always. Both thread tensions can be adjusted on many sewing machines. In a few moments, we’ll show you how.
Automatic thread tension is available on some sewing machines. When you’re sewing, this feature sets the tension based on your current task. The fine-tuning will sometimes have to be done by you, however. Your stitch length may need to be adjusted manually for specific fabrics and thread types.
Fabric Type and Thread Tension
Several factors contribute to the specific characteristics of the fabric, including its thickness, texture, and fiber composition. In addition to determining how a fabric feels and drapes, they also determine how it runs through a sewing machine. The interaction between a fabric and a thread is also determined by them. Consequently, different thread tensions will be best suited to different fabrics.
More delicate threads and tighter tension are generally required for lightweight fabrics. On the other hand, you’ll need to use a looser tension when sewing heavier fabrics with thicker thread.
Thread Type and Thread Tension
Tensions can be adjusted on many types of threads. It is, however, essential to match.
In terms of weight and fiber composition, make sure your top and bottom threads are the same. Cotton threads should be used with cotton threads, lightweight threads should be used with lightweight threads, etc.
The thread should also be matched to the fabric. Threads for lightweight fabrics should be lighter; threads for heavier fabrics should be heavier. Synthetic fabrics should be sewn with synthetic thread, while natural fabrics should be matched.
You should also keep in mind that poor-quality thread can damage your sewing machine’s tension disks in several ways. You may find that your disks are covered in dust and debris as a result. As a result, your disks may wear out faster, and the tension mechanism may become clogged.
What You Need to Know About Needles
If you use the wrong needle, you can have tension problems with your sewing machine. The thread is guided through a hole in the fabric through the needle. It is impossible to hold the thread optimally if the needle hole is too large. As a result, the tension of the top thread can be affected. As a result, puckering may occur, or other problems may arise because of unbalanced stitches.
- Make sure you use only high-quality thread
- Ensure that the top and bottom threads are the same
- Thread your fabric according to its type
- Choose the right needle
- It is necessary to tighten the tension on lighter fabrics and loosen the tension on heavier fabrics.
How Should a Sewing Machine Tension Be Set?
This question cannot be answered in a one-size-fits-all manner. Tension settings must be adjusted according to the type of sewing. Tension adjustment mechanisms are not labeled the same way by all sewing machine manufacturers. There are, however, a few guidelines that may be helpful.
The tension dials on most sewing machines will have numbers 0 to 9 or 1 to 10. Lower numbers indicate lower tension, as you might expect. Likewise, a middle number, such as 5, means you’re using a medium tension, which is a good choice for general-purpose purposes.
The automatic setting is indicated by an “A” on the tension dial. Several things can be meant by this.
The tension of your sewing machine is selected based on a variety of factors, such as the thickness of your fabric and other variables.
The thread tension may be adjusted according to the stitch type on other machines. You may still need to make manual adjustments, however, since these adjustments don’t account for fabric type or thickness.
It is possible to find a universal or “automatic” tension on mechanical and lower-end computerized machines that works well for a variety of sewing types. Again, you may need to adjust for fabric thickness and type.
Test stitches are a good idea when in doubt. A high tension will cause your fabric to pucker. The tension is too low if the stitches are loose.
Our troubleshooting guide will discuss how incorrect tension can cause other problems. A sewing machine tension problem can be solved by knowing how to fix it.
How to Adjust Upper Thread Tension
When you have problems with thread tension, it’s usually the top thread that’s at fault. The top thread’s tension on most sewing machines can be easily adjusted.
Your tension mechanism should be checked to ensure it is operating correctly. Gently tug on the upper thread with your presser foot lowered. A tight thread indicates that the mechanism is working. You may need to consult a sewing machine repair professional if this is not the case.
Next, determine whether you are experiencing too much tension or not enough tension. To adjust the tension of your sewing machine, use the dial or knob on the machine. Tension increases with a more significant number. After each adjustment, check whether further adjustments are needed by sewing a few test stitches.
It is vital that your stitches are even, without loops or nests. Your line of stitching should not pucker. It is not acceptable for the bottom thread to show through on top and vice versa.
How to Adjust Bobbin Tension
As we already mentioned, most tension problems will be caused by the upper thread. It may not be the bobbin thread that is the problem, but the relative tightness of the threads to one another, even if the lower thread appears to be the problem, such as loops on the fabric surface.
Adjusting the top thread is easier than adjusting the bottom thread. Be sure to also:
- Make sure your bobbin is wound correctly
- The sewing machine has been threaded correctly
- Ensure that the tension mechanism is clean and free of debris
- The needle you’re using is suitable for the thread and fabric you’re using
- There is a match between the bobbin thread and the fabric thread
- The following instructions will help you adjust sewing machine bobbin tension if the lower thread really does need to be adjusted.
How to Adjust Tension on a Side-Loading Bobbin
It is necessary to remove the bobbin case. The side of the device has a small screw. You should tighten or loosen the screw very gradually while the bobbin is still in the case. Each quarter-turn should be completed slowly.
How to Adjust Tension on a Drop-In Bobbin
Drop-in bobbin sewing machines have bobbin cases that look different from side-loading bobbin sewing machines. The adjustment will also be made here.
Your sewing machine’s bobbin case needs to be removed. Locate the screw after removing the bobbin from the case. You’ll find it near the thread-holding spring at the front. One quarter-turn or one half-turn at a time should be adjusted slowly and gradually.
Are Tension Adjustments the Same for Every Make and Model?
No, unfortunately. There may be slight differences in thread tension regulation between different sewing machine models and makes. There are, however, some general principles that apply. You can adjust your sewing machine’s thread tension if you understand these general principles.
Every sewing machine’s top thread travels along an obstacle path from the spool to the needle. Different sewing machines follow different paths. The purpose remains the same as long as you keep your upper thread from tangling and regulate its tension.
Arrows and numbers are usually used to mark the path between thread guides on sewing machines. Verify that you’ve followed the thread guides correctly if you’re experiencing tension issues.
Tension disks and a tension regulator are part of your sewing machine’s tension assembly.
It is through tension disks that the thread passes before it reaches the needle that it is tensioned. Tension is created by the disks squeezing the thread. Tension regulators control the amount of pressure exerted on threads by disks. You can adjust the pressure by using the tension knob or dial on your sewing machine.
While some machines have knobs for adjustments, others have dials, the principle is the same for all sewing machines. On knobs and dials, the numbering may also differ. There are also sewing machines that have automatic or universal settings that others do not.
You should first check your regulator to ensure it is set correctly for the type of sewing you are doing if you are experiencing tension problems. Make sure your disks are clean and, if necessary, remove any dust or debris.
Troubleshooting Sewing Machine Tension
Following your understanding of thread tension and how your sewing machine regulates it, let’s consider tension-related problems in more detail.
You Should First Confirm That Tension Is a Problem
Consider whether thread tension regulation is the real problem before turning the tension dial. A number of other reasons can cause threads and stitches to fail. Here are a few things to consider first.
Sewing Machine Needle
New needles of the right size and type should always be used to begin a new project. Your needle should not be bent or damaged in any way, and it should be properly installed. Damaged, incorrectly installed, bent, or damaged needles can cause several problems, including:
- Broken threads
- Loose stitches
- Uneven stitches
- Fabric damage
- Skipped stitches
- Thread shredding
Make sure to check out our article on how to shred fabric.
Check Your Thread
Your project should be threaded with the appropriate weight. Are you using the right thread? Natural threads should be used with natural fabrics, and synthetic threads should be used with synthetic fabrics. Is there a match between the upper thread and the bobbin thread? What is the quality of the thread you are using? These are some of the problems you may encounter if you don’t:
- Broken threads
- Fabric puckering
- Fabric damage
Check Your Threading Diagram Twice
Are you sure you have threaded your machine correctly? The following problems may occur if you miss a thread guide, do not thread the tension disks properly, or mix up the threading steps (it happens!):
- Breaking threads
- Thread bunching
- Machine jamming
- Loose stitches
How About Your Bobbin Thread?
A bobbin that isn’t drawing could be sitting incorrectly in its case if the bobbin thread isn’t drawing. Make sure your bobbin is inserted correctly and re-check it.
Fabric puckering can also occur when a bobbin is wound incorrectly.
Check the Spool Cap
Your thread is held on the spool pin by the spool cap. Your thread may jam or break if it’s too tight. It can also cause problems if it’s too loose.
Is Your Presser Foot Down?
It’s common for us to forget to lower the presser foot from time to time. In order to sew, you need to use the presser foot, which activates the tension disks. That’s right: there is no tension on the upper thread. As you can see, it looks like this.
How Clean Is Your Machine?
It is possible for parts of your machine, such as tension disks and tension regulators, to accumulate lint, dust, and grease over time. Your tension assembly may be impeded by this. Make sure your tension assembly is clean if the thread isn’t feeding correctly. You can do it this way.
It’s worth looking at the thread tension if you’ve tried these steps, and they haven’t helped.
Troubleshooting Tension-Related Issues
Your difficulties are caused by tension, so you’re sure that’s the case. That diagnosis needs to be narrowed down.
Which thread is it? The top thread or the bobbin thread?
It’s time to determine if the problem lies with the upper or lower thread once you’ve determined that the problem is tension-related.
It is most common for the problem to appear on the opposite side of the fabric from the thread that caused the problem. In this case, the bottom thread may be responsible for the symptom appearing on the fabric surface. The thread on the top is probably the cause of a problem on the underside of the fabric.
In most cases, the top thread is to blame. The upper thread should be adjusted proportionately to the lower thread, even if it looks like it is to blame.
Is it too tight or too loose?
A Goldilocks solution must be found for thread tension: neither too tight nor too loose. Identifying which adjustment to make it easy with these tips.
There are several signs that one or both threads are too tight:
- The bottom thread comes through to the surface (the top thread is too tight)
- Pulling the top thread through to the bottom (too tight bottom thread)
- Fabric bunching
- Fabric puckering
- Broken thread
- When stretched, stitches break
- Machine jamming.
There are several signs that one or both threads are too loose:
- Gaps in the seam
- Skipped stitches
- Uneven stitches
- For instance, having a loose top thread may cause your stitches to appear this way.
The 10 Most Common Sewing Machine Problems And What They Mean
What might be causing these symptoms, and how to diagnose them.
- Fabric Puckering – The top or bottom thread tension is too tight, the thread is mismatched to the fabric, or the bobbin is wound incorrectly.
- Broken Threads or Stitches – The needle might be damaged, the thread might be too tight, the machine may not be threaded correctly, the tension assembly may be dirty, the thread may be poor quality, and the spool cap may be too tight.
- Skipped Stitches – A loose top or bottom thread; a loose spool cap; a machine that is not threaded correctly; a presser foot that is up; a sewing machine needle that is either damaged or incorrectly installed.
- Uneven Stitches – The top or bottom threads are too loose; the sewing machine needle is incorrectly installed or damaged, and the sewing machine isn’t threaded correctly.
- Gaps in the Seam – The top or bottom threads are too loose, or the spool cap is too loose.
- Loops and Nests – Spool cap too loose, top or bottom thread too loose, machine not threaded correctly, presser foot up.
- Bottom Thread Showing on the Surface – The top thread’s tension is too tight, or the tension of the bottom thread is too tight.
- Top Thread Showing on the Bottom – The bottom thread tension is too tight, or the top thread tension is too tight.
- Top Thread Not Feeding – The sewing machine is incorrectly threaded, the tension assembly is dirty, the spool cap is too tight, the sewing machine needle is wrong, incorrectly installed, or damaged, and the top thread tension is too tight.
- Lower Thread Not Feeding – Thread tension on bobbins is too tight, bobbins are incorrectly wound, and bobbins are positioned incorrectly in bobbin cases.
Do You Have Problems with Thread Tension?
Any project can be plagued by thread tension problems. You can quickly fix or even prevent it once you understand how thread tension works.
However, there are many things that can cause issues that appear to be tension problems but aren’t. It’s also important to note that tension problems aren’t caused by tension regulators – nor are they cured by them.
Other factors that may affect tension should be considered before reaching for the dial:
- What is the gauge of the sewing machine needle you are using? Is it new and undamaged?
- What are the matching threads on top and bottom? Are they matched to each other and to the fabric?
- Have you threaded your machine correctly?
- Do you have a clean and debris-free tension assembly?
The upper thread is usually the source of tension problems. Bobbin threads may be responsible for some problems, however. It is fortunately not difficult to adjust either one.