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9.4

Tying a square knot (reef knot)

Cross right over left, then left over right, and check that the knot lies flat.

Square knot vs granny knot. A square knot, tied right over left then left over right, lies flat with each short end beside its own long part; a granny knot, tied right over left twice, twists and slips.
Fig. 9.4 A square knot, tied right over left then left over right, lies flat with each short end beside its own long part; a granny knot, tied right over left twice, twists and slips. Source: Animated Knots; Wikimedia Commons knot diagrams.
Area: HandsFrom age 11Time to learn: 10 minutes

You will be able to tie a square knot, check that it is tied correctly, and spot a granny knot.

SafetyNever use a square knot to join two ropes that will hold weight or a person. The Ashley Book of Knots, quoted by Animated Knots, warns that using this knot to tie two ropes together has cost lives.

Why it matters

The square knot is the first binding knot most people learn, and it is the base of the usual shoelace bow. Tied the wrong way it becomes a granny knot, which holds even less well. Use it to tie up bundles, bags and bandages, never to join two ropes that will carry a load.

How to do it

  1. Take one end of a cord in each hand. For practice, wrap a cord around a rolled towel.
  2. Cross the right-hand end over the left-hand end, tuck it under, and pull it up. This is a half knot.
  3. Now cross the end that is in your left hand over the end in your right hand, tuck it under, and pull it through. The second cross must go the opposite way from the first.
  4. Pull on both ends at the same time so the knot closes evenly.
  5. Check it. A square knot lies flat and looks like two small loops hooked through each other. Look at one cord: its short end and its long part come out of the knot side by side. The other cord looks the same.
  6. If the knot twists, sits at an angle, or the ends stick out crosswise, it is a granny knot. Untie it and tie it again, saying 'right over left, left over right' as you go.

Common mistakes

  • Crossing the same way twice (right over left both times), which makes a granny knot.
  • Using a square knot to join two ropes for towing, lifting or climbing. It can capsize and pull apart under load.
  • Pulling hard on one end only, which can capsize the knot so it slides apart.
You can do this when …you can tie a square knot around a rolled towel three times in a row and explain each time why it is not a granny knot.

Sources

  1. Animated Knots: Square (Reef) Knot
  2. International Guild of Knot Tyers: Sea Cadet knots

Sources and numbers last checked . How we check

Topic: Knots and bows

Go deeper

GuideHow to tie shoes that stay tiedA common reason laces come undone is a crooked granny bow. Here is how to check yours, the one change that fixes it, and how to teach it to a child.

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1Body16 lessons
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  1. 9.1Tying shoelaces that stay tied
  2. 9.2How to wrap a present
  3. 9.3Addressing an envelope
  4. 9.4Tying a square knot (reef knot) · You are here
  5. 9.5How to tie a clove hitch
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