How to measure thread size?

[Jeff51]

So, faced with a pile of thread of unknown origins…

What is a correct method of measuring the thread size?

I have been making a loop so that I can place two strands side by side in my calibers. I close the jaws until I feel moderate resistance. Then take a reading or three.

Using this method, I’ve been seeing 0.0045 to 0.0055 for typical home sewing machine thread.  0.007 to 0.009 for some “heavy duty” thread.  And 0.012 for some C & C upholstery thread. Which I take to be Tex70.

There are others that don’t quite fit any of the standard sized listed for conventional thread types.

I bought some Tex90 from Amazon (my first mistake). Measured 0.0095. Not even close to the 0.0133. So back it went. I’m now lurking on thread exchange for some proper string.

Are there variations of thickness depending on the manufacturer and thread type as they relate to standard sizing?

So, tell me if my method is sound, and if not, what should I be doing?

I've lurked for years and learned just how much I don't know.  Such a wonderful source of information.  I'm a complete noobe at this, so other basic questions will follow.

Thanks for the help,

All the Best, Jeff

[fredk]

One method I learnt is to wrap the thread tightly around a ruler or stick marked with a couple of inches. Then count how many threads you get to the inch. There is a conversion table somewhere on the internet which converts the threads per inch to regular standard measure

There should be no variation on thickness between manufacturers when using the standard nomenclature. A Tex90 should be the same size no matter who makes it. Thats the whole point of standard nomenclature

[kgg]

2 hours ago, Jeff51 said:

So, tell me if my method is sound, and if not, what should I be doing?

Another method that may also work, since V69 (TEX 70) has a breaking strength of 10.6 lb and V92 (TEX90) has a breaking strength 14.2 lbs you could try tying a length of thread to 14 lb of weight and see if you can lift it without it breaking. If it breaks it is V69 or smaller and if not it is V92. Just be careful that the thread when it snaps doesn't cause an injury to your eyes, etc.

 

2 hours ago, Jeff51 said:

I bought some Tex90 from Amazon (my first mistake).

A lot of the sewing thread listed on such places are from a lot of "unknown manufacturers" (probably Chinese) made thread with consistency all over the place. The best thing is buy a brand name thread like say American & Efird (www.amefird.com) which is made in both Canada and the USA. Brand name companies put the engineering and effort in providing quality thread for a wide variety of applications. Brand name thread is labelled just inside the bottom of the spool with information detailing date of manufacture, thread size, type, brand, etc. Yes, they are more expensive but you get what you pay for without the frustration of contenting with lesser quality thread. I do have some of the cheaper stuff but rarely use it, just not worth the effort.

kgg

[Jeff51]

5 hours ago, fredk said:

One method I learnt is to wrap the thread tightly around a ruler or stick marked with a couple of inches. Then count how many threads you get to the inch. There is a conversion table somewhere on the internet which converts the threads per inch to regular standard measure

There should be no variation on thickness between manufacturers when using the standard nomenclature. A Tex90 should be the same size no matter who makes it. Thats the whole point of standard nomenclature

Thanks for the responses.

I'm not sure my eyes, or patience, is up to wrapping and measuring like that.     kgg, testing strength is an interesting idea.  I have a spring tester I built for measuring recoil springs that could work for this.  If I give it a try, I'll report back.  

Thanks again,  All the Best, Jeff