This knot is quite a strong knot. I have used it to tie the top spar of a balanced lug to the halyard. It held and is still holding just fine. It's almost impossible to take apart. You need a knitting needle or some kind of instrument such as a marlinspike, to pry apart the strands. Even then it's easier to cut it.
One of the most useful application of this knot is to bind the end of a rope that is fraying. Use twine and and tighten it well, then finish the end properly when you have time.
Constrictor knots are also very useful when you are making splices or putting in a grommet let say at the end of a anchor line. It keeps the various strands from unravelling and hold the rope tightly until the splicing is done.
It works best when tied with smaller line. I would not trust a constrictor knot done in anything larger than 3/8 inch.
Tying a Constrictor Knot
To hold this knot needs something behind it. Round and oval shapes are best.
I've made it here with big rope on a quite small dowel so it's not in ideal proportion but with smaller line it is one tough little knot. It took me for ever to learn this one, just didn't want to go in. There are many ways of tying the constrictor knot and a few variations. I first met it when I was working on a farm. It was used to tie up bags of grain, it was called a miller's knot then. If you want to have a chance of ever untying it then make the last step with a folded end of the line so you can pull it out when you want to untie it. It's well worth learning.
Some of my Knot Pages
- Bowline, The Must Know Knot
- Bowline on a bight, how to tie a bowline if you don't have the ends.
- The Anchor Bend Knot
- Cleat Hitch it's surprising how many people can't tie this knot properly.
- Constrictor Knots make it a point of being difficult to untie. it's their job!
- Highwayman's Hitch makes it a point of being easy to untie, good for a quick hitch at the dock or where you need to get it undone fast. Useful if you want to tie your horse so you can untie him for a quick get-away.
- Reef Knots are used to reef sails, otherwise they are very unreliable.
- Rolling Hitch A useful knot that can be tied on another line to pull some slack so you can untie a knot or untangle a winch line.
- Sheet Bend joins 2 ropes together
- The Stopper Knot stops a knot from running out of a cleat. 2 styles
- Truckers Hitch helps tighten a rope around a canoe on a car or on a trailer.
- Farmer's Loop Similar to the Trucker's hitch, easy to tie.
- Round Turn and two half hitches a useful multipurpose knot
- The Fireman's coil keeps your coiled rope from getting tangled.
- Buntline Hitch, a very old knot that has found a new life with modern slippery rope
Materials used for Modern RopemakingTrade Names of materials used for Ropes
Polypropylene rope floats but is sensitive to UV Good for dinghy ropes and water skiing
Nylon rope is strong and absorbs shocks Often found in climbing ropes and mooring or anchor lines.
Polyester makes a strong low stretch rope It is the most common rope material on sailboats. Often used as outside braid in composite ropes.
UHMW (Dyneema) Ropes are ultra strong and chemically resistant but it is very slippery and knots often untie.
Aramid (Kevlar) is very strong but sensitive to shock loads. Chlorine bleach destroys ropes made of aramid.
email me if you find mistakes, I'll fix them and we'll all benefit: Christine