Sewing Thread Numbers Explained: Tex, Ticket, Ne and How to Choose

Few things in garment manufacturing cause more avoidable defects than a misunderstood thread number. Order “40s/2” thinking it means one thing and receiving another, and you get broken threads at high speed, puckered seams, or seams that grin open after the first wash — with no obvious cause at the machine.

The reason is that the trade uses four different numbering systems simultaneously, and two of them run in the opposite direction to the other two.

This single distinction resolves most confusion. Higher Tex = coarser. Higher Ne = finer.

And the ticket number, which is what most people actually buy by, is higher = finer again.

The weight in grams of 1,000 metres of thread. Tex is the ISO-preferred unit and the one to use as your reference currency when converting anything.

• Tex 30 means 1,000 m weighs 30 g
• Smaller Tex = finer thread; larger Tex = thicker thread

The weight in grams of 10,000 metres. Commonly used for filament yarns.

• 1 tex = 10 dtex
• Tex 17 = 170 dtex

The weight in grams of 9,000 metres. Dominant for filament threads and for hosiery-type yarns. Conversion to and from Tex is exact:

Denier = Tex × 9 → Tex = Denier ÷ 9

The number of 840-yard hanks that weigh one pound. Despite the name, this system is also used for embroidery threads of any fibre — a legacy of embroidery threads historically being cotton.

Ne = 590.5 ÷ Tex (synthetic fibres)
Ne = 583.1 ÷ Tex (natural fibres, i.e. cotton)
Ne ≈ 588 ÷ Tex (common blends)

The small differences in constant are why conversions between mills sometimes disagree by a fraction. Where accuracy matters, specify in Tex.

The number of metres of single yarn that weigh one gram.

• Nm 40 means 40 m of yarn weighs 1 g
• Nm = 1,000 ÷ Tex

The trade shorthand printed on many cones. The smaller the ticket number, the thicker the thread.

Metric ticket number ≈ resultant Nm × 3 = (1,000 ÷ resultant Tex) × 3

Two cautions:

1. The ticket number tells you nothing about plying. A Tkt 40 could be 2-ply or 3-ply — different constructions, same ticket.
2. Different makers have historically used their own ticket scales. Always cross-check against the Tex figure.

A label like 40/2 or 60/3 carries two pieces of information:

• First number = the count of each single yarn (40 or 60). Higher = finer singles.
• Second number = the number of plies twisted together.

So 40/2 = two 40-count singles plied together.

To get the resultant count of a plied thread in an indirect system, divide the single count by the number of plies:

The non-obvious point: a 60/3 can be stronger than a 40/2. It uses three plies, even though each individual single yarn is finer. Never infer strength from the first number alone.

Full worked example — 100 % polyester 40s/2:

Composition 100 % polyester · yarn size 40s (= Ne 40) · 2 plies. Tex = 590.5 ÷ 40 × 2 = 29.5, so this thread is the familiar Tex 30 general-purpose sewing thread. Its ticket number ≈ 1,000 ÷ 29.5 × 3 ≈ Tkt 100.

Comfortable working ranges by application:

Specifying Tex alone is a common mistake. Construction matters at least as much as size.

One widely-missed risk: standard polyester degrades under sustained UV. Anything going into a car interior, a boat cover, a convertible top or outdoor furniture should be specified as anti-UV, not simply “polyester”.

Needle sizing uses a dual notation — Nm/US (e.g. 80/12) — where the metric figure is the blade diameter in hundredths of a millimetre. An Nm 80 needle has a 0.80 mm blade.

The working rule: the thread should occupy roughly 40–50 % of the needle eye diameter. Too small an eye and the thread shreds and breaks from friction and heat; too large and you get skipped stitches and poor loop formation.

A mismatched pair is also the most common cause of needle heat at high machine speed, which is what melts synthetic thread rather than abrading it.

Conditioning matters: textile test results are only comparable when samples have been equilibrated under standard conditions. The reference is ISO 139, standard temperate atmosphere: 20 ± 2 °C, 65 ± 4 % RH.

1. Start with seam requirement, not thread. Specify the seam strength needed; the thread follows.
2. Give Tex, plus construction. “Tex 30 core-spun polyester” is a specification. “40s/2” is not.
3. Match the needle using the 40–50 % eye-fill rule.
4. Set colourfastness requirements explicitly — which ISO 105 tests and which grey-scale ratings must pass.
5. Set a shrinkage limit if the garment will be washed.
6. Specify heat and UV resistance where relevant; standard polyester is not UV-stable.
7. Consider machine speed. Higher speeds need better lubrication and often a finer filament core.
8. Define put-up and packing — cones in 1,000 / 2,000 / 3,000 / 5,000 m, cops or king spools, and units per carton.
9. Request certification — OEKO-TEX® STANDARD 100 (Class I for babywear), plus recycled-content documentation where rPET content is claimed.

Two single yarns of 40-count plied together. The first number is the fineness of each single yarn, the second is the number of plies.

Tex is a direct measure of mass per 1,000 m — higher Tex means thicker thread. Ticket number is trade shorthand where higher numbers mean finer thread. Approximate conversion: metric ticket ≈ resultant Nm × 3.

No. “wt” is a domestic sewing-thread convention, not the same scale as Tex. Confusing the two is one of the most common specification errors. Specify in Tex to avoid the ambiguity entirely.

Core-spun polyester in the Tex 40–70 range for construction seams, with a heavier colour-matched polyester for topstitching if you want a visible stitch line.

Finer. A Tkt 120 thread is much finer than a Tkt 40.

You can, but cotton has minimal stretch and higher shrinkage than polyester. For knit seams that must recover after stretching, polyester or cotton-wrapped polyester core performs better and shrinks less.

Almost always one of three things: the needle eye is too small for the thread (friction and heat), the twist direction is wrong (snarling and looping), or lubrication is inadequate for the machine speed and fabric density.

Values and conversion formulae in this guide are standard textile industry references, rounded for practical use. Confirm critical figures against your supplier’s technical datasheet and your own seam trials.

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