USA technical standard for thread
Types
| I | twisted soft multiple cord |
| II | twisted bonded multiple cord |
| III | bonded mono cord |
| IV | soft air entangled |
| V | bonded air entangled |
Classes
| 1 | Normal Elongation |
| 2 | Heat Stable |
Subclasses
| A | General Purpose |
| B | Non-Wicking Finish |
| C | Unfinished |
Sizes
- 8
- 7
- 6
- 5
- 4
- 3
- FF
- F
- E
- B
- AA
- A
- OO