How to Adjust Tension On Industrial Sewing Machines?

Sewers that are being trained by knowledgeable sewers are sometimes uneasy about adjusting the tension on their industrial sewing machine for different factors. However, you should never hesitate to alter the tension on the sewing machine thread if it changes the type of thread, fabric, needle, or you buy a different sewing machine.

But What is the Tension of an industrial Sewing Machine?

Tension adjustment is controlled by a succession of mechanisms separately controlling the bobbin thread (lower thread) and the needle (upper thread), applying tension (or force) to the latter in order to form strong, balanced stitches. The tension of the sewing machine may be modified based on the requirements of each seamstress by working the needle thread and the bobbin thread simultaneously or independently.

Are your Stitches Well Balanced?

A thread that frequently produces loops or has unbalanced stitches is often indicative of your machine’s tension. Figuring the way this out, upstream, can help you get a better sense of how to work on the problem. When the stitches are well balanced, they should be the same on both sides of the fabric and be evenly spaced. The upper thread, as well as the lower thread, must not show up at the top and underside of the weave, respectively. The stitch formed with each puncture of the needle shouldn’t be visible, it ought to be embedded in the fabric. If something tends to move easily when you’re tightening it, this suggests that there is a tension issue.

What Solution to Industrial Sewing Machine Tension Problems?

  • The Lower Thread is Visible on the Top of the Seam
    When bobbin thread appears on the wrong side of the fabric being sewn, it can indicate two things:
    • The tension controlling the upper thread, passing through the needle, is too tight. It then pulls the bobbin thread up.
    • The tension controlling the lower thread, coming out of the bobbin, is too loose. The upper thread tension then takes over.
  • The Upper Thread is Visible on the Underside of the Seam
    When the needle thread appears on the other side of the fabric, it can mean two things:
    • The tension controlling the lower thread is too tight pulling the needle thread down.
    • The tension controlling the needle thread is too low.

A number of options exist for both of these problems.  Before making any changes in the needle or bobbin thread tension settings, first, inspect your sewing machine to make sure that there are no abnormalities affecting its functioning adequately.

  1. To help you, get the instructions for your sewing machine.
  2. take apart the spool and the upper thread that passes through the needle. 
  3. Remove the bobbin (and its case), then clean the location with a brush. 
  4. Make sure that the path the upper thread has to follow before meeting the needle eye is free of debris.
  5. The greatest needle possible can help you get the best results with your sewing. If your needles have been overused, it is a great idea to change your needles. 
  6. Check that the thread you’re using is appropriate for the textiles that you’re sewing. 
  7. The thread in your machine may not be correctly threaded, so consider following the suggestions in the instruction manual in order to secure your sewing machine.
  8. Pull the bobbin out of its place to make sure the thread is unwinding in the correct direction when you use the bobbin.

Throughout all these assessments, if the stitches remain unbalanced, we’ll need to push the method to get more details.

Are You Using the Same Upper and Lower Thread Type?

An industrial sewing machine typically produces the best results at the “low” or “automatic” tension settings using threads of both the same material. When using threads of different materials to make your sewing components, it is likely that these threads do not have the same physical properties. In this situation, voltage adjustments will likely have to be made.

Adjust the Needle Thread Tension

No matter what the issue is Always begin by altering that tension in the top thread i.e. the thread that is used for needles. Most of the time the tension of the needle just needs to be adjusted or decreased in order to attain an appropriate tension. The top tension is generally set by a number dial that is located in the center of the unit, or through knobs specifically designed for electronic machines.

  • To increase the tension of the needle to increase the tension, rotate the dial slightly towards a higher value (clockwise).
  • If the thread on the bobbin needs more resistance, reduce the tension of the upper thread by moving the dial to a lower amount (counterclockwise).

Adjust the needle thread tension repeatedly until you get the desired results. Sometimes, adjusting the needle thread tension isn’t enough to get well-balanced stitches. In this instance, the thread tension of the bobbin is to be monitored in turn.

Adjust the Bobbin Thread Tension

A lot of people are reluctant to alter the thread tension lower on their sewing machines, however, it is possible that this method gives the most effective outcomes. However, it is advised to use this method only for last-resort purposes after you’ve tried all alternatives previously suggested. It is, in fact, quite unusual to be required to alter the tension on the thread on the bobbin.

Adjust the Vertical Bobbin Thread Tension

The adjustment of a tension of a bobbin made from metal that is found within the Singer Initial or the Singer Tradition 2273, for instance, can be accomplished by loosening or tightening a screw on the back of the bobbin’s casing. It is the most significant screw that can be used to control the tension. Rotate the screw clockwise to increase tension, or turn the screw counterclockwise to reduce it. To make sure that the tension on your thread is adjusted correctly it is possible to use the method known as a yo-yo. It involves securing your thread at its ends and letting it hang from the bobbin just a couple of centimeters up in the air. When you jerk the bobbin a few times, watch what happens.

The thread doesn’t unwind but it does so very slowly. If the tension is too high you should let the screw loose.

The thread is able to unwind by itself. The tension is weak which is why it is essential in order to tighten it.

The thread is unwinding around 2 or 3 cm but does not fall completely. The voltage is in the right range.

Adjust the Horizontal Bobbin Thread Tension

For models of sewing machines like that of Brother FS40 with a horizontal bobbin case that is located beneath the needle, it’s also possible to alter the tension of threads after a few adjustments. Take off the transparent bobbin case and then loosen the needle case. After that, remove the black box to open the screw for tension adjustments. Be cautious, if your sewing machine is equipped with two screws, it’s the screw with a slot. To increase tension, make the screw tighten clockwise, and reverse the direction. To decrease the tension, you’ll be required to reduce the tension counterclockwise.

What Number Is Tighter Tension On A Sewing Machine?

The dial settings vary from zero to nine, therefore 4.5 is typically the ‘default location for straight-stitch sewing. This should work with the majority of fabrics.

If you’re using a zig-zag or any other stitch with wide width, then you could notice that the thread of the bobbin is pulled to the top.

In order to create a stitch that is properly formed it is necessary to have both threads. Both threads have to function together so that they connect exactly at the center of the material. If there is a gap, it will cause one to push the other onto the other part of the material. This can result in a low-quality stitch that will not be able to hold.

Since the tension of the bobbin is set by the factory, it can’t normally be adjusted to accommodate normal sewing. Therefore, we’ll only be talking about the top tension as that’s where you’d normally adjust the tension. The dial settings vary from zero to nine, therefore 4.5 is typically the ‘default location for straight-stitch sewing. This should work with the majority of fabrics.

If you’re using a zig-zag or any other stitch with wide width, then you could notice that the thread of the bobbin is pulled to the top. It could show on the edges of the stitch, and the fabric appears slightly raised or the fabric is bunched. If you observe this, reduce the tension (perhaps between 3 to 4). The fabric will then lie lower. It is also helpful to ease off the tension at the top slightly if you’re topstitching and you want the stitches to become more prominent. The tension settings can vary between different machines. The thread’s thickness and the weight of the fabric can affect the tension. Don’t be scared to try different settings and determine the ideal setting for your particular project.

How do you adjust the bottom tension on a sewing machine?

Adjust the thread’s upper and lower tension

  • Make sure you insert a brand new needle. If the needle appears fine to you, it’s crucial that you follow the same procedure.
  • It is recommended to utilize the same thread at the top and the bottom. The higher the thread’s quality the more gorgeous and even the stitch.


In the event that you notice that the tension (the stitches) on the edge of the fabric

Not correct, it means it is because the tension on the thread on the lower (on both the bobbin and bobbin) isn’t correct.

If the tension in the middle of the fabric isn’t equal,

This means that the tension of the upper thread isn’t correct or the machine has not been threaded correctly.

Lower thread settings

There are two types of hooks 

1 CB-hook horizontal shuttle

Take the capsule out and the bobbin. Re-insert the bobbin as illustrated in the illustration.

Check whether the thread is tight by dropping it and then securing the thread. Shake it a few times.

If tension is in the right place the thread will begin to get a bit looser (about 1 cm).

2 Vertical shuttle

For adjusting the tension to adjust the tension, turn the screw located on the back of the cartridge.

Take the capsule out and the bobbin. Re-insert the bobbin as illustrated in the diagram.

Some vertical shuttles might look like different ones, but do not be concerned it’s identical.

Use the thread guide into the hook, while keeping the bobbin in place. The thread will pass through into the tensioner’s groove.

If you pull your thread back, it is important that the bobbin must remain horizontal even though the cap has been removed.

Now do a test:

  • Make use of a normal material and stitch at minimum two layers of fabric together
  • Start by testing straight stitch using the length of the stitch from 2.5 to 3
  • Then you can test the zigzag stitch by using length 3 or 4 and width 2.

It is also very important to perform regular maintenance on your machine.

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