Filament Sewing Thread: Thickness vs TEX or TKT

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When it comes to filament sewing thread, the thickness of the thread is often measured in terms of its Tex or TKT value. Tex is a unit of measurement that represents the weight in grams of 1000 meters of thread, while TKT is a unit of measurement that represents the length in kilometers of one kilogram of thread.

How to choose TEX or TKT?

The thickness of filament sewing thread is generally inversely proportional to its Tex or TKT value. In other words, the higher the Tex or TKT value, the thinner the thread. For example, a thread with a Tex value of 30 is thinner than a thread with a Tex value of 50. The thickness of the sewing thread in the picture below is: TEX 135, TKT 20

Size 138 Bonded Polyester Thread
Size 138 Bonded Polyester High Strength Sewing Thread

Tex or TKT values are useful for comparing the thickness of different threads, especially when buying thread from different manufacturers. However, it’s important to note that Tex or TKT values are not standardized, so a thread with a Tex value of 50 from one manufacturer may be a different thickness than a thread with a Tex value of 50 from another manufacturer.

Satess®Plus Bonded Nylon Thread Size Parameters

TEX METRICLENGTHRA
(dTex)
BSA
(cN)
EBA
(%) 
DHS
150℃(%)
35Tkt 0802,000M395217024<3.0
45Tkt 0602,250M585329024<3.0
70Tkt 0401,500M851475025<3.0
90Tkt 0301,500M1126620025<3.0
135Tkt 0201,500M1710963027<3.0
210Tkt 013900M23901470030<3.0
270Tkt 010750M32751822030<3.0
400Tkt 008600M40852069030<3.0
Bonded Nylon Thread Size Parameters

When choosing filament sewing thread, consider the Tex or TKT value as well as the intended use of the thread. Thinner threads are generally better for lightweight fabrics, while thicker threads are better for heavier fabrics and heavier-duty sewing tasks. It’s also important to choose a high-quality thread that is strong and won’t break easily during sewing.