Big Fly Thread – 400 Denier
Designed specifically for big saltwater flies, bass bugs, and other tying applications where a very strong, easily-handled thread is necessary. Made from the same polyester material as UNI 6/0 and 8/0 threads, it won’t dull fly-tying scissors. Four times stronger than a 6/0 thread and four times thicker. Untwists quickly and easily for flat-thread applications.
| Specification | Detail |
|---|---|
| Denier | 400 |
| Material | Polyester |
| Length | 100 yards |
| Strength | 4 times stronger than 6/0 thread |
| Application | Big saltwater flies, bass bugs, tying applications |
FAQ
Is this thread compatible with standard fly-tying scissors?
Yes, it is made from the same polyester material as UNI 6/0 and 8/0 threads, so it won’t dull fly-tying scissors.
How does the strength compare to standard 6/0 thread?
This thread is four times stronger than a 6/0 thread.
Can it be used for flat-thread applications?
Yes, it untwists quickly and easily, making it suitable for flat-thread applications.




Nathan Jones –
Used this thread for tying bass bugs and it held up well in saltwater conditions. Strong and easy to work with. The untwisting is smooth and doesn’t fray. Great for large flies.
Sophie Sanderson –
Felt much more durable than regular 6/0 thread. Works well with my fly-tying scissors without any dulling. Perfect for heavy-duty saltwater fishing.
Victor Mathis –
Strong and reliable for big flies. A bit thicker than expected, but that’s fine for the application. Easy to untwist and manage during tying.