Coats plc
Embroidery | Sewing Solutions | Tips & Hints | Setting The Correct Tension
Tips & Hints - Setting The Correct Tension
No single set of adjustments on an embroidery machine contribute more to overall embroidery quality than ensuring the thread is run at the optimum tension. Productivity will also be enhanced as poor tension is one of the leading causes of thread breakage on the machine

It can be a complicated affair as there are two aspects to consider:

Bobbin thread tension: only one thread needs to be tensioned and it is best to set the bobbin thread tension first as this will control the tensions of all the top threads

Top thread tension: as many as fifteen different top threads need separate adjustment to ensure perfect tension on each needle - being not too loose and not too tight.

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The programme illustrated above get each different needle to embroider the letter 'H' to demonstrate the top thread tension of that needle.

It is important that you ensure the bobbin tension is adjusted correctly (see table below) so that the top thread tension rings can be adjusted individually without needing to touch the bobbin checkspring again.

All tension settings are best assessed by turning the embroidery over and judging the appearance from the back.

The ideal settings show that the bobbin thread should capture 30% of the available width on the back of the lettering.

Assuming the bobbin thread tension to be correct each top thread can be individually adjusted until correct tension is achieved.

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Analysis of the above:

You can see that the quality of embroidery varies considerably between each row of needles; assuming the bobbin tension is set at 35g (for Coats alcazar) then only the red row of 'H's' have the correct top thread tension; the top row of blue 'H's have too tight a tension and the yellow row have too loose a tension and require adjustment so that the bobbin thread occupies 30% of the letter width as illustrate in the centre row.

Tension Test programme: you can download a suitable programme in Tajima format depending on how many needles you need to test - click on the links below to download the programme to suit your machine:

9 needles per head
12 needles per head
15 needles per head

Please ensure you set up your machine so that each needle embroiders a separate letter

Thread tension meter:

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The device illustrated above is the most accurate way of assessing thread tension and is available from all good embroidery machine stockists and accessory companies.

The correct thread tension is as follows:

Coats Thread Type
Top thread tension (g)
Bobbin thread tension (g)
Coats Alcazar - viscose rayon
Coats Sylko - trilobal polyester
Coats Sylko Metallic - metalised polyester

Tips & Hints