Semperfli Nano Silk 100D Fly Tying Thread

Built for serious fly tyers, this ultra-strong GSP tying thread delivers exceptional performance for salmon, predator, saltwater, streamer, nymph, and dry fly patterns—especially when spinning deer hair. Renowned by professionals worldwide, it offers unmatched strength-to-diameter, with a breaking strain of approximately 3,800 g / 8.4 lb and a composition that’s up to 10 times stronger than steel of the same diameter.

Designed to excel on a wide range of hooks commonly used for larger trout, bass, and saltwater flies, this thread maintains rock-solid tensile strength while laying perfectly flat. That means no unwanted thread build-up, cleaner heads, tighter dubbing loops, and smoother, more precise finishes—even after multiple wraps. Its slick, durable fibers resist fraying and snapping under heavy tension, giving you the confidence to torque down materials, cinch spins, and secure bulky profiles with ease.

Ideal for deer hair work, articulated streamers, predator patterns, and saltwater applications, this premium thread adapts seamlessly to both modern and traditional tying techniques. Whether you’re forming compact, dense hair heads, locking in synthetics, or building tidy, low-profile bodies, it handles it all with control and consistency.

• High-tenacity GSP tying thread
• Approx. 100 denier / 6/0 classification
• Breaking strain: ~3,800 g / 8.4 lb
• Lays perfectly flat with no build-up
• Outstanding for deer hair spinning and strong material control
• Trusted by professional fly tyers worldwide

If you demand a low-bulk, super strong thread that won’t let go under pressure, this is a go-to choice for building durable, high-performance flies.