Nail knot
A nail knot is a compact line-to-line knot used to attach fly line to backing, or to tie a butt section or leader directly to fly line.
- Group
- Loops & line-to-reel
- Category
- Knots & rigging
- Level
- Intermediate
- Water
- Fresh & salt
Last updated
What Nail knot means
This knot gets its name from the classic method of tying it around a nail or small tube. The nail acts as a temporary mandrel so the wraps stack neatly, then you slide the knot off and snug it down onto the line.
Many anglers use a nail knot for backing-to-fly-line connections, especially when the fly line has no factory loop. It is also used to attach a short butt section or a leader directly to the fly line, though many anglers choose a loop-to-loop connection for faster leader changes.
A nail knot is slim and smooth through the guides. The tradeoff is that it is not quick to change once it is tied and tightened, so it is usually treated as a semi-permanent connection.
Why it matters on the water
A clean, tight nail knot keeps the backing connection small enough that it does not hang up when it passes through the rod guides. That matters when a fish runs far enough to put the knot into the guides, or when line management gets messy in wind.
Knowing when to use a nail knot versus a loop-to-loop connection helps with rigging choices. Nail knot when you want a low-profile, durable connection. Loop-to-loop when you want fast leader swaps and easy troubleshooting.
Read next
- Arbor knotA simple knot used to attach backing to the reel spool arbor. It tightens under tension so the backing grips the spool instead of slipping.
- BackingBacking is thin, strong line spooled onto a fly reel under the fly line. It adds extra length for long runs and helps the fly line fit the reel correctly.
- Fly lineThe fly line is the thick, weighted line that loads the fly rod and carries the cast. It connects the reel and backing to the leader.
- Loop-to-loop connectionA loop-to-loop connection joins two lines by passing each loop through the other, then pulling tight. It is commonly used to attach a leader to a looped fly line or a sink tip to a running line.