How to Tie the Constrictor Knot
The Constrictor
The Constrictor Knot is a powerful binding knot (or hitch knot) used to tightly secure objects by gripping them with exceptional strength. It is valued for its ability to cinch down firmly and resist loosening, making it one of the most effective binding knots in practical use. Because of this combination of security, simplicity, and gripping power, the Constrictor Knot is commonly used for bundling materials, tying off sacks, securing rope ends, and fastening objects that require a tight, reliable binding.
Other Names: Gunners Knot, 'Worlds Most Dangerous Knot'
Constrictor Knot Instructions
The Constrictor Knot is widely used in sailing, camping, construction, crafts, and general rope work whenever a strong binding knot (or hitch knot) is needed. Its structure resembles a Clove Hitch with an additional crossing turn that locks the knot tightly against the object being bound. This design creates significant friction and constricting force, allowing the knot to grip securely even when subjected to vibration or movement. The Constrictor Knot is included in The Ashley Book of Knots and is widely regarded as one of the most effective binding knots ever.
Many call this the ‘Most Dangerous Knot in the World’ among other clickbait nicknames.
Key Considerations
Proper dressing of the Constrictor Knot is important to ensure the knot functions as intended. The crossing turn should be positioned neatly and tightened evenly so that the knot grips the object uniformly. Careful dressing and setting help maximize holding power and reduce the likelihood of the knot shifting or loosening. As with all binding knots, the finished knot should be inspected before use to confirm that it is properly formed and securely tightened around the object.
Advantages & Disadvantages
One of the key advantages of the Constrictor Knot is its exceptional holding ability. It can be tied quickly, requires minimal rope, and grips so tightly that it often remains secure even when other binding knots would loosen.
However, this same characteristic can make the knot difficult or impossible to untie after being heavily loaded, often requiring it to be cut free. In addition, the Constrictor Knot only works well around cylindrical objects. Square or rectangular objects will not work as effectively as a cylindrical object.
Despite this limitation, its reliability and strong constricting action make it a favourite among sailors, craftsmen, and rope enthusiasts whenever maximum binding strength is required.
ABOK #1249 - The Constrictor Knot
ABOK Numbers: Abok# 176, Abok #355, Abok #364, Abok #430, Abok #1188, Abok #1189, Abok #1249, Abok #1250, Abok #1251, Abok #1252, Abok #2052, Abok #2097, Abok #2489, Abok #2560, Abok #3441, Abok #3700, Abok #3853
It is widely accepted that the Constrictor is a versatile and effective binding knot, both for larger ropes (but not too large) and smaller ropes, leading down to twine. It serves as a great binding knot and can be used as a hitch knot as well. Very effective as a hitch, I might add…until you have to untie the thing.
Because of this knot’s success, the number of ABOK entries is too many for me to print here. I have included all the numbers so you can see too many of them yourself!
The entries I listed are as follows:
Abok #176,
‘When a dynamite cartridge is to be exploded with a fuse, employ a CONSTRICTOR KNOT (#1249 and #1252). Pull the two ends tight and it will hold as if adjusted with a ratchet. The hole in cartridge should be made with a stick of soft wood, and the fuse inserted full length.’
Abok #355,
‘If double gangings with two hooks are used as shown in #352 they may be secured with a CONSTRICTOR KNOT (#1249), which is more secure than a CLOVE HITCH (#1177) or a RING HITCH (#1859).’
Abok #371,
‘The same result may be reached with cord and a CONSTRICTOR KNOT (1249). Cover the top with a piece of heavy paper or cloth and tie a CONSTRICTOR close under the collar of the bottle.’
Abok #1249,
‘The CONSTRICTOR KNOT. At the time when the sinnets of Chapter 39 were being made there was no knot that would hold secure the large number of strands that were required for some them. For a while seizings were employed, which served the purpose well but took too much time to tie. Then the knot shown here was evolved, which proved in every way adequate. So long as the CONSTRICTOR is tied over a convex surface it will not slip. It draws up easily, has a ratchetlike grip and is the most secure of all BINDING KNOTS. In the twenty-five years and more that have elapsed since I first tied the knot, I have shown it to many people, and a number of fishermen sailing out of New Bedford now use it for whippings and stoppings. It is also used for the same purpose in several chandleries. I have found it convenient for tying any kind of a roll, for hanging Christmas stockings to a crane, and for seizing garden hose and atomizer bulbs.’
Disclaimer
The information on this website is provided for educational and informational purposes only. While every effort has been made to ensure accuracy, knot strength, security, and suitability can vary depending on rope type, condition, load, environmental factors, and how the knot is tied. Users are responsible for inspecting their equipment and verifying that a knot is appropriate for their intended use. Do not rely solely on the information provided here for activities involving personal safety, life support, climbing, rescue operations, heavy lifting, or other high-risk applications.
SCB Media Group assumes no responsibility or liability for any injury, loss, damage, or consequences resulting from the use or misuse of the knots and techniques described. Always seek professional instruction and follow applicable safety standards where appropriate.