How to Tie a Constrictor Knot

Steps

1. 1How will you tie it?

   Both ways give exactly the same knot, and neither is better tied. The only question is whether the end of the object is free.

   Think before you tighten: this is a knot you commit to. A constrictor is meant to seize, and a firmly set one usually has to be cut off rather than untied. Set lightly, in thick or stiff line, you can sometimes work it loose by hand.

   This is a binding knot and nothing else: use it to hold something closed or hold something together. It is not a loop to put over a post, not a hitch to hoist with, and not for anything taking a person's weight. Reach for a knot meant for that job instead.

   Never around a finger, wrist or limb: a constrictor bites harder the more it is pulled, and it will cut off circulation. Practise on a bundle, a sack neck or a length of pipe.

   Pass it around the object

   Works on anything you can get the line around, including a pipe running into a wall.

   1. 
      1a

      Wrap it twice and tuck the end

      Pass the rope around the object. Bring the working end back over the standing part. Pass around the object a second time. The strand now lying diagonally across the top is the riding turn. Tuck the working end under the riding turn and the standing part together. Before you pull it home, check where the ends come out. On a constrictor both ends come out close together near the middle, trapped under the strand crossing over them. If they come out at the outside edges running parallel, you have tied a clove hitch. That still grips a little, but it will not bind the way a constrictor does. Slide it off and start again. Once the ends look right, pull both ends tight.

   2. 1b

      Optional: tie the slipped version

      If you want the knot to come undone more easily, finish that final tuck with a bight instead of the working end. This slipped version releases faster. Even so, it can still be hard to undo in some rope materials when you work it very tight.

   3. A bight is not a loop: a bight is a doubled section of rope, made by folding the line back on itself without crossing it. A loop crosses. When you tuck a bight instead of the end, a folded tail sticks out of the finished knot. Pull that tail and the knot collapses.

   Drop a loop over a free end

   Faster, but only for something with a free end, like a bundle of loose rope.

   1. 1a

      Drop the loop, twist it, and drop it again

      Drop a loose loop over the end. Reach under the loop and grab it at the crossing point. Twist it half a turn to form a figure 8. Pass the loop over the end a second time, taking it over the crossing point as you go. Before you pull it home, check where the ends come out. On a constrictor both ends come out close together near the middle, trapped under the strand crossing over them. If they come out at the outside edges running parallel, you have tied a clove hitch. Slide it off and start again. Once the ends look right, tighten it.

   What you have just tied: a constrictor is a half knot sitting under the riding turn. It is close to a clove hitch, and the difference is that one end passes under the other. The riding turn then wedges that crossing against the standing part, and that is what makes it bind rather than merely hold.

2. 

3. 
   2

   Cut it off when you are done

   Look at the knot. A slipped constrictor leaves a folded tail, a bight, sticking out of it. If you see that fold, pull it. The knot should collapse, though a hard set one in some rope can still resist. Otherwise plan on cutting it, because a set constrictor jams. Put your eye protection on first. Cut the riding turn, which is the strand lying diagonally across the top, where it crosses over the turns underneath. Those turns take the blade and protect the rope or the object you bound. Cut away from your hand, and keep your face and body out of the line of the knot. Expect the binding to spring when it parts.