Serger Tension Tips

If your serger doesn’t include an automatic tension function, any adjustments are usually made manually by turning a dial. While the settings numbers are typically unique to different serger manufacturers and models, the highest number usually denotes the highest tension setting.

Finding the right tension setting on a serger can be complicated – especially for beginners. Some consider threading a serger the most difficult part of the set-up process, but properly adjusting the tensions takes far more practice to get it right. You can even create additional stitch variations by tweaking tension settings.

A high tension setting puts more pressure on the thread as it moves through the serger, creating tighter stitches. The trick is leaning to create the perfect tension balance between the multiple threads moving through the loopers and needles to create the perfect stitch.

Tension Basics

Many serger instruction manuals and DVDs give you a head start by including a list of proper tension settings for commonly used stitch options and fabrics. But it’s also important to try out different settings on your own. Consider threading the machine with different brightly-colored threads. This will help you identify which threads need adjusting. Make one adjustment at a time on each length of fabric, then take note of the tension setting that works best. Keep each sample for future reference.

Below are a few common tension problems and how to identify them.

Unbalanced Looper Tensions

• When the upper looper tension is set too high, it will pull down on the lower looper thread to the point that the fabric will begin to ‘tunnel,’ or roll downward. That pressure also causes the lower looper thread to pull up on the left needle thread.
• Conversely, when the upper looper tension is too low, it provides no resistance for the lower looper thread. This causes loose, wavy stitches on the backside of the fabric.
• When the tension on the lower looper thread is too tight, it behaves in the same manner as a too-tight upper looper tension setting, except that it pulls up on the left needle thread.
• If the tension setting on the lower looper is too low, it will be pulled over to the front side of the fabric by the upper looper thread.

Needle Tension

Needle tension settings have slightly more leeway than looper tensions, but they’re just as important in producing a professional finish on garments and projects.

There are a couple of signs to look for when the thread tension on the left needle is too high. The fabric will pucker slightly along the line of stitches. This is most evident on knit fabrics. Second, it will pull the lower looper thread in front of the stitch. You’ll get a worse result when the thread tension on the right needle is too high: it will pull the lower looper thread completely through the fabric.

If the right needle thread tension is too low, the thread will be obviously loose on the front of the stitch while hanging in loops on the back of each stitch. A low tension setting on the left needle thread will produce such a loose stitch that it will be visible (like a too-loose seam) on the front of the fabric and small loops on the backside of each stitch.

Serger Tension Tips

• Choose lower tension settings when working on heavier fabrics or multiple layers, which use more thread. Do the same when using heavy or stretchy threads.
• Use higher settings for sheer and lightweight fabrics, as they need less thread when serging edges.
• Tension settings should be lowered when using a long or wide stitch setting and tighten the tension on short or narrow stitches.

Becoming skilled in the various tips and tricks used by expert or professional serger users is a learning process. But as with any creative effort, the beauty and quality of the final products you produce will demonstrate your dedication to learning this craft.