Sewing thread weights 30w 40w 50w
Wt and Gunze numbers
The most common sewing thread weight system tells the length of sewing thread needed for one kilogram in kilometers. Thus, a higher weight or wt number means a thinner and finer yarn. The sewing thread weight system was derived from the Japanese Gunze weight number practice, which uses two numbers separated by a dividing line. The first number corresponds to the number of the wt system and the second tells the number of threads that make up the yarn. It is common for the thread to be twisted from three strands of the same weight.| Wt weight figure | Gunze number notation | Applications | |
|---|---|---|---|
| Light | 60 wt | #60/3 | Bobbin thread or appliqué |
| Thin | 50 wt | #50/3 | Bobbin thread or appliqué |
| Usual | 40 wt | #40/3 | Patchwork |
| Upholstery | 30 wt | #30/3 | Ornamentation |
| Heavy | 20 wt | #20/3 | Ornamentation |
The number following the dividing line indicates the number of threads that make up the ready-to-use sewing thread. The threads are twisted together to form the actual sewing thread, which we then use in our sewing work.
The problem with the Wt weight number is that it can be the same regardless of the number of strands used in the yarn, although the properties of the yarns differ according to the number of strands. In Gunze numbering, these threads are distinguished by the number of strands. The higher the first number, the thinner the thread (for example, 50/2 thread is thinner than 30/2). The second number tells how many threads the thread is twisted from. Thus, 50/3 yarn is heavier than 50/2 because it has three strands of 50 weight twisted together.
For more details, for example, on Wikipedia: https://en.wikipedia.org/wiki/Thread_(yarn)