What does "TEX" mean for thread?

[SewLiz]

Looking through my wawak sewing catalog, most of the threads have just a TEX # (no weight #), but then a few have TEX and WT (which is different than the tex )... so I don't get it. Thanks.

[MRoy]

WIKIPEDIA says: Tex is the mass in grams of 1,000 meters of thread. If 1,000 meters weighs 25 grams, it is a tex 25. Larger tex numbers are heavier threads. Tex is used more commonly in Europe and Canada.

A common Tex number for general sewing thread is Tex 25 or Tex 30. A typical silk buttonhole thread suitable for bartacking, small leather items, and decorative seams might be Tex 40. An upholstery thread, Tex 75. A more decorative but still heavy duty topstitching thread for coats, bags, and shoes, Tex 100. A topstitching thread suitable for luggage and tarpaulins, Tex 265-Tex 290. But a fine serging thread, only Tex 13. For blindstitching and felling machines, an even finer Tex 8.

Hope this helps!

[Sandy Navas]

Hey, Myrna, that was truly enlightening. Never knew that. Must be similar on the numbering of threads that we're used to here - but the smaller number on threads in the US is usually a larger weight thread . . . hmmmm.

[MRoy]

I didn't know it either Sandy and I've got a cone of thread that has a TEX #. Guess I need to check it now that I know what it means.

Hey, Myrna, that was truly enlightening. Never knew that. Must be similar on the numbering of threads that we're used to here - but the smaller number on threads in the US is usually a larger weight thread . . . hmmmm.

[Denis]

A third measurement is "denier". so , there's WT TEX,and denier.

[Jean Sewing Machine]

You guys and gals are fonts of knowledge! Thanks for the info.

[Carrie J]

You learn something new everyday! Thanks Liz for the post, and thanks Myrna and Denis for the information! What a great place to learn!

[Sandy Navas]

A third measurement is "denier". so , there's WT TEX,and denier.

and he didn't explain denier . . . that means off for a google search which tells me:
de·ni·er¹
noun

• 1.
  a unit of weight by which the fineness of silk, rayon, or nylon yarn is measured, equal to the weight in grams of 9,000 meters of the yarn and often used to describe the thickness of hosiery.
  "840 denier nylon"

[K. McEuen]

Oh, so when using the thread labeled TEX, you aren't supposed to wear a cowboy hat and yell "Ya-Hoo!" while sewing?

[Jean Sewing Machine]

From what I read on Superior thread website TEX #s mean the opposite of WT. Higher TEX are thicker, while higher #s in WT mean finer thread. I think most thread in the retail market go by the weight number. It is all very confusing.