Semperfli Classic Waxed Thread – 18/0 Bulk Spool
Semperfli Spyder ready waxed thread is a premium choice for fly tyers seeking durability and natural blending in small fly patterns. Developed from a traditional tying thread, Spyder features two fine strands twisted together, providing enhanced strength and a semi-translucent appearance that matches the shade of the fly pattern.
With a breaking strain of approximately 400gm, Spyder offers significantly greater strength compared to standard threads like Uni Caenis (85g) or Danville Spiderweb (142g), giving confidence when tying delicate small flies.
The waxed finish helps the thread lay flat during tying, improving pattern accuracy and presentation. Ideal for anglers who prioritize both strength and visual realism in their fly designs.
| Specification | Detail |
|---|---|
| Thread Type | Spyder (2-strand twisted) |
| Size | 18/0 |
| Breaking Strain | Approximately 400gm |
| Finish | Waxed |
| Use Case | Small fly tying |
FAQ
What makes Spyder thread stronger than other fly tying threads?
Spyder thread has a breaking strain of approximately 400gm, which is significantly higher than standard threads like Uni Caenis (85g) or Danville Spiderweb (142g). This increased strength comes from its two-strand twisted construction, providing better durability when tying small flies.
Does the waxed finish affect how the thread lays when tying flies?
Yes, the waxed finish helps the thread lay flat and smooth during tying, which improves the overall presentation and accuracy of the fly pattern.
Is Spyder thread suitable for all types of small flies?
Spyder is specifically designed for small fly tying and is ideal for patterns where strength and natural color blending are important. It is best suited for anglers who need reliable performance in delicate fly construction.




Sarah McGrath –
I’ve been using Semperfli Spyder waxed thread for several months now and it’s proven to be much stronger than the threads I used before. The two-strand twist gives it excellent strength, and the semi-translucent quality helps the fly blend naturally with the pattern. It lays flat when tying, which makes my small flies look more realistic.
Ruth Arnold –
This thread is a game-changer for small fly tying. The breaking strain is impressive, and I’ve never had a thread fail during a cast. The waxed finish keeps it from fraying and helps it stay in place when tied.
Stephanie Rutherford –
I appreciate the strength and the natural color match. It’s slightly more expensive than some alternatives, but the performance justifies the cost. I’ve used it on both dry flies and nymphs with good results.