Tex coding for sewing threads for outdoor fabrics

What do the Tex numbers for sewing thread for outdoor fabrics mean? 


Our German supplier of high-quality sewing thread and tent thread, from the well-known Amann brand, codes their sewing threads using various designations, such as the familiar thickness, but also using a so-called Tex number. But what do these specific Tex codes actually mean? As the market leader in sewing threads for outdoor fabrics, we would like to clarify this for you. Below is an explanation that will hopefully shed some light on the matter. First, the Tex numbers of our own sewing threads for outdoor fabrics from Amann:

• Serabond + Outdoor Pro polyester sewing thread: thread thickness 40 = Tex 70 (also coded as V69)
• Serabond + Outdoor Pro polyester sewing thread: thread thickness 30 = Tex 90 (also coded as V62)
• Serafil polyester sewing thread: thread thickness 20 = Tex 135
• Serafil polyester sewing thread: thread thickness 10 = Tex 270
• Rasant polyester/cotton sewing thread: thread thickness 25 = Tex 120
• Rasant polyester/cotton sewing thread: thread thickness 35 = Tex 80
• Rasant polyester/cotton sewing thread: thread thickness 50 = Tex 60

The Tex system and numbers for sewing threads. A calculation

In addition to the existing separate thread thicknesses, there is also the so-called Tex system (ISO 1144:2016). This is the most widely used international system for indicating and measuring the fibre and thread fineness of sewing thread. Because the cross-section is not a suitable reference size, particularly for natural fibres, due to natural variations, determination based on length and weight (weight numbering) has become the norm. The fineness (formula symbol Tt) is indicated by the unit “tex”. For fibres and filaments, the unit ‘dtex’ (decitex) is also often used.
Tex = weight in grams per 1000 m (g/km), ktex = 1000tex = g/m, dtex = 1/10tex = g/10,000 m, mtex = millitex = 1/1000tex = 0.001 g/km.
1 tex = 1 g/1000 m
1 dtex = 1 g/10,000 m

Conversion from dtex to den: den = dtex*0.9
Conversion from den to dtex: dtex = den/0.9
Conversion from tex to Nm: Nm = 1000/tex
In other words: the higher the Tex number, the coarser and heavier the sewing thread or fibre. The fibre fineness of the linear textile product therefore decreases as the Tex number increases.

The best-known coding for sewing thread: thickness

Amann sewing threads (Rasant, Outdoor Pro, Serafil, Serabond) are also coded with thicknesses:
10, 20, 35, 40, 60. The lower the number in relation to thickness, the stronger and thicker the thread. In other words: “10” is the thickest thread, followed by decreasing thicknesses. Thickness 50 (in the polyester/cotton blend) is somewhat the standard sewing thread for tent fabric, and thickness 40 (polyester) is standard for boat covers. As the market leader in outdoor fabrics and sewing threads for those outdoor fabrics, we always know which thread you need for which application. Click here to contact us directly.