Tension Talk: Fine-Tune Your Upper Thread Tension for Flawless Stitches

On a BERNINA machine, the Upper Thread Tension is set automatically when a stitch pattern is selected. The tension setting is shown in the Upper Thread Tension icon in the Status Bar. 

 B 990 screen

7 Series screen shown which is similar to the current 4 & 5 Series screen

The default Upper Thread Tension is set at the BERNINA factory using Mettler thread size 100/2 in the upper and bobbin thread. If a different type of sewing thread is used, the upper thread tension may need to be adjusted.

The Upper Thread Tension can be changed by tapping the Upper Thread Tension icon.

B 990 screen

7 Series screen shown which is similar to the current 4 & 5 Series screen

Adjusting Upper Thread Tension on Your BERNINA Machine

The thread tension dialog window provides the current stitch pattern tension value. When adjustments are made, the display highlights the change—yellow on the B 990 or a yellow box on other models—while maintaining a black dot on the slider to indicate the default setting.

Steps to Adjust Upper Thread Tension:

1. Tap the +/- icon or move the slider up.
2. Use the Multi-function knobs (noted by two dots on the display).
3. Higher tension values pull the bobbin thread further into the fabric, creating tighter upper thread tension.
4. Lower values reduce tension, keeping the bobbin thread deeper in the fabric.

The Status Bar icon updates to reflect the new tension setting. On the B 990, a dynamic image visually illustrates the changes.

Resetting Tension to Default:

• Tap the yellow value box or the black dot on the slider.
• Navigate to Main Menu > CLR icon.

Upper thread tension adjustments apply to the current stitch pattern and return to default once the machine is powered off.

Alternate Tension Adjustment:

• On the B 990, go to Main Menu > Settings > Sewing > Upper Thread Tension.
• On other models, access Set Up > Sewing Settings > Upper Thread Tension.

Changes made in Settings override defaults for all stitches and persist even after turning the machine off. These adjustments are shown in the tension dialog window and can be reset if needed.

Keep Making Stitches!