Constrictor Knot
Bind that must not walk. Crossed riding turn is the lock. Expect to cut it.
Intermediate · Polyester / Nylon rope / Polypropylene / Natural fibre
Connection card
Constrictor Knot
For reef / bind.
Two crossing turns on the spar, working end tucked under both — a constrictor that binds.
This card does not say how strong the knot is. A retention figure comes from a bench, in one material, at one diameter, tied by somebody who ties it all day — and the line in your hand is none of those. What it does tell you is whether the thing you have just tied is the thing the record describes.
What this plate is telling you
Bind that must not walk. Crossed riding turn is the lock. Expect to cut it.
Save this as a picture and it works with a dead signal and a nearly dead battery, which is when a joint is most often tied badly. The rest of this page — the steps, the seating sequence, the failure modes and the bench — is for the evening before.
Why this knot
What it earns its place with, what it costs, and what to reach for instead.
- A bind you must release (reef knot)
- A join
- Around a finished piece you cannot sacrifice
- Tucking the end under itself only, which leaves a clove hitch
- Tying it against a flat surface
- Letting the first turn drift while making the second, leaving a gap between the turns
- Expecting to untie it after pulling it hard
- Reef KnotBeginner
Binding two ends of the same line around a sail or bundle
- Clove HitchBeginner
Hanging a fender off a rail or stanchion, or a quick tie you stay beside and adjust
Before you start
- ·Tie it around something curved, such as a rope end, a sack neck or a pole. On a flat surface the turns cannot grip.
- ·Expect to cut it off. Once pulled hard it is often impossible to undo with fingers, so plan to cut the diagonal turn where it lies over the other turns.
- ·If the binding has to come off later, tie a slipped constrictor, finishing the end as a bight so a tug on it releases the knot.
- ·It binds one object. To join two ropes, use a bend.
Step 1 of 4 · move 1 of 1. Pass the end around the object and bring it across over the standing part
Space plays or pauses. Keys 1, 2, 3 and 4 set the speed. Arrow keys change the move.
swipe to step
01.1
Pass the end around the object and bring it across over the standing part
- Hold:
- Left hand holds the standing part against the object
- Move:
- Right hand takes the end round and back across the front, over the standing part
You should now see: One turn around the object with the end lying diagonally across the standing part.
Pass the end around a round object, then bring it across over the standing part so the two cross on the front.
One turn around the object with the end lying diagonally across the top of the standing part.
Tying it against a flat surface, or trying to use it to join two ropes. On a flat face the turns cannot grip and the knot loosens.
Fix: Tie it around something curved, such as a rope end, a sack neck or a pole. To join two ropes, use a bend.
Why: The knot needs a curved surface so the crossing turn can press down on the knot beneath it.
- Used as a join — A bind is not a bend. Pick a sheet bend or Zeppelin if you needed a join.
arrow keys work
Tying procedure — Constrictor Knot
Step 01 / 4
Pass the end around a round object, then bring it across over the standing part so the two cross on the front.
You should now see: One turn around the object with the end lying diagonally across the top of the standing part.
If it goes wrong: Tying it against a flat surface, or trying to use it to join two ropes. On a flat face the turns cannot grip and the knot loosens.
Fix: Tie it around something curved, such as a rope end, a sack neck or a pole. To join two ropes, use a bend.
Why: The knot needs a curved surface so the crossing turn can press down on the knot beneath it.
Step 1 of 4 · move 1 of 1
Pass the end around the object and bring it across over the standing part
Hold: Left hand holds the standing part against the object
Move: Right hand takes the end round and back across the front, over the standing part
You should now see: One turn around the object with the end lying diagonally across the standing part.
Step 02 / 4
Take the end around the object a second time, close beside the first turn.
You should now see: Two turns around the object side by side, with the diagonal crossing lying over them on the front.
If it goes wrong: Letting the first turn slacken or drift while you make the second, which leaves a gap between the turns.
Fix: Hold the crossing under your thumb and push the turns together before you tuck.
Step 2 of 4 · move 1 of 1
Take the end around a second time, close beside the first turn
Hold: Left hand keeps the first turn and the crossing in place
Move: Right hand takes the end round the post a second time, below the first turn
You should now see: Two turns side by side, with the diagonal crossing lying over them on the front.
Step 03 / 4
Tuck the end under itself where it crossed the standing part, then carry it on under the first turn, so it passes under both turns.
You should now see: The end and the standing part leaving the knot in opposite directions, crossed over each other in an overhand beneath the diagonal turn.
If it goes wrong: Tucking the end under itself only. That is a clove hitch: lift the diagonal and the two ends lie side by side instead of crossing.
Fix: Loosen the end and carry it on under the first turn as well.
Why: The diagonal turn clamps the overhand underneath it. That clamp is what grips, and it is why the knot is so hard to undo.
1Under the first turnStep 3 of 4 · move 1 of 1
Tuck the end under itself and on under the first turn
Hold: Left hand holds the standing part
Move: Right hand tucks the end under the diagonal and under the first turn
You should now see: The end and standing part leave opposite ways, crossed under the diagonal — not parallel.
Step 04 / 4
Pull both ends hard to close the knot down on the object. To remove it later, cut the diagonal turn where it lies over the other turns.
You should now see: Turns bedded into the object, no gap under the diagonal, and a knot that does not turn when you twist it.
If it goes wrong: Expecting to untie it after pulling it hard. Once set, it is often impossible to undo with your fingers.
Fix: Cut it off over the other turns. If the binding has to come off later, tie a slipped constrictor, finishing the end as a bight so a tug on it releases the knot.
Why: Cutting the diagonal over the turns beneath it lets those turns protect the rope or object from the blade.
Step 4 of 4 · move 1 of 1
Pull both ends hard; plan to cut the diagonal when it has to come off
Hold: Left hand holds the standing part
Move: Right hand pulls the end until the turns bed into the object
You should now see: Turns bedded into the object, no gap under the diagonal, and a knot that does not turn.
What this is based onAccuracy check, not yet tied · 2 known limits
- Record
- Reviewed 2026-08-14. 2 sources are cited for this record.
- Drawing
- Passed an accuracy check, and a tying video is cited for it. Not yet tied from the drawing. Recorded 2026-09-23.
- Strength
- Not established. No credible, comparable strength data exists for this knot, so no figure is shown.
What the drawing does not show
- Step 2, move 1 of 1: The second turn hangs beside the post instead of going round it.
- Step 3, move 1 of 1: The tuck under the first turn cannot be followed; the end disappears into the knot.
Watch the tie
Drawn from this knot's sequence — the same rope as the steps. Not a recording of hands. It does not start until you press play.
Another recording
How to Tie the Constrictor Knot - ITS Knot of the Week HDITS Tactical / Imminent Threat Solutions · Opens on YouTubeAn outside recording of this construction. It is not the drawing above, and nothing here loads from YouTube until you follow the link.
Seating sequence — where failures are born
The step list compresses the finish. Run these phases in order, one at a time.
01 Form
Build the structure loose enough to see every turn.
None. Shape first.
02 Dress
Nest every turn. Crossed parts will walk or jam.
Light — hold the shape.
03 Set
Load the standing part so the intended turns take the strain.
Working load, not a snatch.
04 Check
Confirm the lock still breaks or inspects as the job requires.
None extra.
05 Commit
Only load it after the structure reads correct. Wrong means remake.
Working load, not a snatch.
Finished structure — what correct looks like
Drawn from a rope model of this knot: which strand passes over which comes from where the rope actually lies.
- Structure
- Around, cross, around again, tail tucked under the standing part and the first turn — crossed riding turn on top
- Standing line
- Riding turn locks both ends against the object
- Tag end
- Tail under the standing part and the first turn — missing that tuck is a clove
- Wraps
- Two turns plus the riding-turn tuck — a clove is not this
- Seating
- Dress hard. Plan to cut it
Verify before you load it
Every line is pass or fail. One fail means retie — do not load a knot you argued with.
- 01Around, cross, around again, tail tucked under the standing part and the first turn — crossed riding turn on top
- 02Dress hard. Plan to cut it
- 03Tail under the standing part and the first turn — missing that tuck is a clove
- 04Two turns plus the riding-turn tuck — a clove is not this
- 05No riding-turn tuck is a clove and will walk
- 06Dressed hard. Need a release? That is a reef knot
Field notes — dark, cold, gloves
- ·Dress is the lock. A pretty knot that is not dressed is not finished.
- ·HMPE usually wants a splice, not a hitch you learned in polyester.
- ·If you cannot break or inspect it under the load you expect, it is the wrong job.
When this family fails, it fails as these. The recovered end still outranks the name.
Directional bite on a standing part — slide-test before you trust it.
- !Turns on the wrong side of the load
- !Failed slide-test, still used
- !A clove where a rolling or icicle third turn was the job
- !It is tied on a flat surface, where the turns cannot grip and the knot loosens
- !The end is tucked under itself only, leaving a clove hitch without the clamped overhand that grips
- !It has been pulled hard and needs to come off, as it is often impossible to untie and has to be cut
Left as a clove — no riding-turn tuck
Bind walks; this is not a constrictor
The tail must tuck under the standing part and the first turn · step 03
Expected to untie after a hard dress
Knife job on a bind you needed to release
Animated Knots: usually cut rather than untied · step 04
Used as a join
A bind is not a bend
Pick a sheet bend or Zeppelin if you needed a join · step 01
Bind walks, or will not come off when you need it to
Check
- ?Crossed riding turn over the two ends
- ?Tail under both
Then
- →Finish the tuck
- →Cut it if it has seated
- →Use a reef knot if you needed a release
Left as a clove — no riding-turn tuck
Check
- ?Bind walks; this is not a constrictor
- ?Inspect step 03
Then
- →Retie. Do not dress a defective structure and call it seated.
Expected to untie after a hard dress
Check
- ?Knife job on a bind you needed to release
- ?Inspect step 04
Then
- →Retie. Do not dress a defective structure and call it seated.
Used as a join
Check
- ?A bind is not a bend
- ?Inspect step 01
Then
- →Retie. Do not dress a defective structure and call it seated.
Same failure class, different geometry. Open the plates — Diagnose still starts from the symptom.
Get it right with everything in your favour0/5 clean
Nothing logged on this knot yet, so it starts on the bottom rung.
Good light, dry hands, a table. Until the sequence is automatic here there is nothing for the harder rungs to test — you would only be learning that difficult conditions are difficult, which you already knew.
How · Tie it, check it against the list, log it. Five clean and the ladder opens.
Nothing marked. Log it clean, or mark what happened first.
Strength, and where the number comes from
Not established
A binding knot, usually cut rather than untied; no publisher states a rope-break percentage for it and the quantity would not describe what it does.
Percentages come from published tests on their own line, their own knot-tyer and their own pull rate. Yours is a different system. Treat a figure as a reason to test, not as a result you already have.
- Animated Knots — Constrictor Knot (Rope End Method)
- ITS Tactical / Imminent Threat Solutions — How to Tie the Constrictor Knot - ITS Knot of the Week HD
Cited tying video already attached to this record.
Record reviewed 2026-08-14
Vetted references
- Animated Knots — Constrictor Knot (Rope End Method)
Animated Knots by Grog
- How to Tie the Constrictor Knot - ITS Knot of the Week HD
ITS Tactical / Imminent Threat Solutions
Related knots
Check the finished knot against what correct looks like before you load it.