OK, just to be clear Apparel Search is not a fan of the word "Thread" as a unit of measure. However, the British have been here before we arrived... Thread has a different meaning in regard to textiles so this is a bit confusing.
We have read that the following definition, "Thread is a cotton yarn measure, equal to 54 inches (1.37m)." However, we have also found some where else that 1 thread is 55 inches. So which is it? Is it 54 inches or 55 inches?
Please use the following at your own risk...
British standard yarn measures:
Note: this is different than thread count. Thread count or threads per inch (TPI) is a measure of the coarseness or fineness of fabric. It is measured by counting the number of threads contained in one square inch of fabric or one square centimeter, including both the length (warp) and width (weft) threads.
You may want to visit the following websites to learn more about thread:
Thread Weights & Measures (Superior Threads)
Thread Numbering (Coats)