FIXED LOOP · MONO / BRAID
This knot can cost you a lure before it ever catches you a fish, and the way it does that is almost always the same: the working loop goes through a gap that looked right instead of one somebody checked. The twist opens several gaps that all look interchangeable at a glance. Only one of them is. The King Sling builds a fixed loop out of a twisted doubled section, with the working loop fed through that one specific opening. It’s documented in heavy mono and in braid. Fused superlines like NanoFil are the exception, and they behave differently enough that they’ve got their own knot — don’t try to make this one do that job.
Five stages, and one of them decides everything
What holds it
Monofilament, heavy leader included, and braid.
Loop size
Set it before the final cinch. The finished loop doesn’t adjust, so guess wrong and you’re retying, not fixing.
What it’s actually best for
A strong fixed loop in mono or braid, not speed. NanoFil testing has favored its own dedicated doubled-line knot over the King Sling, so I don’t force this one onto material it wasn’t built for.
Job
An end loop, or a loop to a lure or hardware, anywhere you want the loop strong and fixed.
The twist makes several openings, and only one of them is the right one
The doubled line twists around itself and every crossing you put in opens another gap. They all look interchangeable. They aren’t. The working loop goes through the one specified opening and gets pulled through from there, and that single choice is the difference between a knot that locks and a handful of slack line the first time you load it. It’s also the step everybody rushes, because by then the twist is fighting your fingers and you just want it done. Slow down there. Look at the gap before the loop goes anywhere near it.
Keep the twist from unwinding while your hands work
- Double the line to form the intended loop size.
- Twist the doubled section the required number of times while keeping crossings orderly.
- Identify the correct opening created by the twist sequence.
- Pass the working loop through that opening without letting the twist unwind.
- Wet the mono and draw the knot down evenly.
- With braid, set it firmly and check that it isn’t slipping before you trim.
Failure clue
The loop went through the wrong opening — that’s the one to check for first, because it looks exactly like a finished knot until it lets go. The twist unwound while you were cinching it, usually because a hand relaxed too early. A fused superline slipped, which is a material mismatch more than a tying error. Or the loop came out oversized and now it’s fouling the hardware it’s tied to. If your first few attempts fall apart in your hands, that’s an ordinary way for this knot to go. The fix is usually keeping the twist count honest, not pulling harder at the end.
The material list is where this one gets picky
Use: fixed loop in mono/heavy mono or verified braid. Skip: NanoFil/fused line without material-specific testing. Compare: Kreh/Rapala for lure-action loops; Perfection/Surgeon’s End for leader-end loops.
How I confirm the opening before I trust it
Before I pull anything tight, I trace the working loop back through the twist with my finger, opening by opening, until I’m sure I’ve got the right gap rather than just a plausible-looking one. That thirty seconds of checking is cheaper than losing gear to a lure that comes off on the second cast. NetKnots’ King Sling page is worth having open the first handful of times you tie this, mainly because seeing which opening is correct in motion beats guessing from a still diagram.
Open the deeper knot workflowJob, material, route, dressing, seating, pull-test checks and the standardized comparison record.
THE SIX-MOVE CHECK
Job → Material → Route → Dress → Seat → Test
- Job. Name what the connection has to do before choosing the knot.
- Material. Confirm the line, leader, rope, wire, and hardware actually suit this structure.
- Route. Trace every pass before tightening anything.
- Dress. Put strands, wraps, and loops in their intended order with no accidental crossings.
- Seat. Tighten in the order this knot needs. More force does not repair bad geometry.
- Test. Inspect the finished shape, load it by hand when appropriate, and retie if anything moves or fails the article-specific checks.
Practice / pass test. Tie this knot three clean times without rushing. A tie passes only when it matches this article’s What to check before you trust it geometry, shows none of the listed failure clues, and survives the stated load/inspection test. If you cannot tell why one attempt is better than another, keep practicing—the lesson is recognition, not memorization.
KNOT SPEC
King Sling — the short answers
- ALSO CALLED
- No widely used alternative name. Its origin is not well documented, so treat any single inventor story you read with caution. It is used mostly by lure and trolling anglers who want a strong fixed loop.
- KNOT TYPE
- Fixed end loop built from a twisted doubled section
- WHAT IT CONNECTS
- A fixed loop at the end of the line, or a loop straight to a lure or item of hardware, wherever the loop should be both strong and fixed. Not a line-to-line knot.
- LINE TYPES
- Monofilament including heavy leader, and braid. Fused superlines such as NanoFil are the documented exception — they have their own doubled-line knot and this one is not a substitute.
- STRENGTH BAND
- High for a loop knot in the materials where it seats cleanly. Its doubled-line structure gives it a different load path from simple overhand-based loops, but published comparisons do not justify calling it universally strongest. Use the correct opening, test the actual line, and choose by loop control and repeatability as much as by reputation.
- DIFFICULTY
- Intermediate to advanced, for one reason: the twist opens several gaps that look interchangeable and only one is correct. Nothing else about it is hard. Not a knot to teach a child first.
- STEPS AND WRAPS
- Six moves. The twist count is the thing to keep honest — enough turns to lock, kept orderly so the crossings stay readable. Braid needs the same count but a firmer final set.
- TIE TIME
- A home knot, or a knot for an unhurried deck. Forty-five seconds to a minute once fluent, and longer whenever you stop to confirm the opening, which you should.
- POOR CONDITIONS
- Poor. Identifying one gap among several near-identical ones is exactly what cold hands, wind and low light take away from you. Tie these in advance where you can.
- THROUGH THE GUIDES
- Compact once set, and better behaved through guides than most doubled-line loops. It is usually tied at the lure, so the question rarely arises.
- LUBRICATION
- Yes in mono, before you draw it down evenly. In braid the lubrication matters less than the firmness of the set — braid will creep quietly if you finish it politely.
- TAG END
- An eighth of an inch in mono, a little more in braid, which creeps under load. Trim only after a hard pull has confirmed nothing is moving.
- TOOLS
- None required. Nippers to trim, and good light while you are still learning which opening is the right one.
- BEST SUITED TO
- Not species-specific — chosen by the rig. Common on trolled and cast lures on heavy mono and braid, in king mackerel and other coastal lure fisheries, and anywhere a strong fixed loop is worth the extra time.
The strength bands are rough on purpose. Published knot tests don’t agree with each other — the same braid-to-leader knot has tested near ninety percent of line strength on one machine and under half on another, because the line brand, its diameter, how fast it got cinched, whether it was wet and whose hands tied it all move the number more than the knot does. Read the band as where this knot sits next to its neighbors, not as a figure to quote.
FIELD INTELLIGENCE
Where it earns its place, and where it costs you
Advantages
- It is a doubled-line loop, so it keeps more strength than the single-strand loop knots that do the same job.
- The loop stays open and fixed, so a lure hangs on a pivot — jerkbaits sit level, small crankbaits start their wobble sooner, and jigs fall with the head free rather than pinned.
- It works in both mono and braid, which few loop knots in this group do.
- The finished lock is compact for a doubled-line knot.
- It is easy to verify once tied: trace the working loop back through the twist and either it went through the right gap or it did not.
Disadvantages
- The twist creates several openings that look alike, and picking the wrong one gives you a knot that comes apart on the second cast.
- It is slow, and it is unforgiving of the conditions that make everything slow — cold, wind, dark.
- The twist unwinds if a hand relaxes while you cinch, and there is no way to recover it halfway.
- It should not be forced onto fused superlines, which have a dedicated knot for good reason.
- Loop size is fixed at the set, and an oversized loop fouls the hardware it is tied to.
- It buys nothing on lures already hung on a split ring or a snap.
Use a different knot when
- Non-Slip Loop / Kreh Loop — when you want a lure-action loop you can tie fast, in the dark, with cold hands
- Rapala Knot — when the bait is on mono and you want a simpler finishing path
- Perfection Loop or Surgeon’s End Loop — when the loop is a leader-end loop for a loop-to-loop join
- The dedicated NanoFil knot — when the line is a fused superline, where this one is the wrong tool
WHAT TO CHECK BEFORE YOU TRUST IT
This is the loop you tie when you want the strength of doubled line and the freedom of an open loop at the same time, and you have a minute to spend. The freedom is real on baits that swim: a suspending jerkbait hangs level and darts wider, a small crankbait wobbles a shade earlier, a jig falls head-free. It is wasted on anything already fitted with a split ring, snap or swivel. Do two things — trace the working loop back through the twist with a finger before pulling anything tight, and set the loop size on purpose, because loop size is the variable almost everyone leaves to chance.
What actually makes it fail
- The working loop pushed through the wrong opening, which looks right and lets go under load.
- The twist unwinding as the knot is drawn down, usually because a hand released early.
- A polite final set in braid, which leaves the lock creeping instead of locked.
- Tying it in a fused superline, which is a material mismatch rather than a tying error.
- An oversized loop that fouls the hardware or catches the hook point on the cast.
How to test it, and how it ages
Before anything is pulled tight, trace the working loop back through the twist with a fingertip, gap by gap, until you are certain of the opening rather than merely hopeful. Then wet mono and draw it down evenly, keeping tension on the twist so it cannot unwind. Finished, it should show a compact twisted lock and a loop that has kept its size. Pull hard and steadily: if anything stretches or the loop shrinks, it is not set, and in braid that means it will creep.
Over a session: Good once correctly set. The lock is stable and does not loosen with casting. Watch the loop where the hardware rides on it, and in braid check after the first few hard loads that the tag has not crept.
Troubleshooting
Why did my lure come off on the second cast?
The working loop went through the wrong opening. Retie and trace the path with a finger before you tighten anything — the gaps look alike and only one locks.
Why does the twist keep unwinding while I tighten?
You are letting go of one side too soon. Keep tension on the doubled section with the hand that is not pulling until the lock has closed.
Can I use this on NanoFil or other fused line?
No. Testing there favors that material’s own doubled-line knot. Use it rather than forcing this one.
Why does it creep on braid when it holds fine on mono?
Braid needs a firmer set than mono. Pull it hard before you trust it, leave a slightly longer tag, and check it again after the first real load.
My loop keeps coming out a different size each time.
Loop size is decided when you double the line, not at the end. Set the doubled length against the lure eye before you start twisting.
