reef knot

Reef knot
Names	Reef knot, Square knot (from its appearance)
Category	Binding
Efficiency	48%
Origin	Ancient
Related	Thief knot, granny knot, grief knot
Releasing	Jamming
Typical use	Joining two ends of a single line to bind around an object.
Caveat	Not secure as a bend. Spills easily if one of the free ends is pulled outward. Does not hold well if the two lines are not the same thickness.
ABoK	#1402

The reef knot or square knot is a common and simple binding knot. It is used to connect two ropes of equal size.

A reef knot is formed by tying a left-handed overhand knot and then a right-handed overhand knot, or vice versa. (Two consecutive overhands of the same handedness will make a granny knot.) A common mnemonic for this procedure is "right over left, left over right", which is often appended with the rhyming suffix "... makes a knot both tidy and tight".

The working ends of the reef knot must be both at the top or both at the bottom, otherwise a thief knot results.

Uses

The reef knot is used to tie two ends of a single line together such that they will secure something that is unlikely to move much. It lies flat when tied with cloth, and has been used for bandages for millennia. It's also one of the most common knots used in surgery. With both ends tucked (slipped) it becomes a good way to tie shoelaces, whilst the non-slipped version is useful for shoelaces that are excessively short. It is also used decoratively and to tie the Obi (or belt) of a martial arts keikogi. Finally, it is quite handy for tying plastic garbage or trash bags, as the knot forms a handle when tied in two twisted "ears".

This knot's name originates from its use to "reef" sails (tie part down to decrease effective surface area), where its easy-spilling behavior was very handy. A sailor could collapse it with a pull of one hand; the sail's weight would make the collapsed knot come apart.

The reef knot is one of the key knots of macrame textiles.

Misuse

The reef knot can capsize (spill) when one of the free ends is pulled outward.

The reef knot's ease of tying and visually appealing symmetry belie its weakness. It is popular as a general-purpose binding knot. In particular, it figures prominently in Scouting worldwide, known more popularly as the square knot. In the Boy Scouts of America demonstrating the proper tying of the square knot is a requirement for all boys joining the program, and the knot is pictured in the international membership badge.

The International Guild of Knot Tyers warns that this knot should never be used to bend two ropes together. A proper bend (such as the double fisherman's knot) should be used instead. Some knotting guides claim that misused reef knots cause more deaths and injuries than all other knots combined.^[1] Further, it is easily confused with the granny knot, which is a very poor knot.

Related knots

Reef (square) knot

Thief knot

Granny knot

Grief knot

See also

• List of bend knots
• List of binding knots
• List of knots
• Square knot (emblem or insignia)

References

• Ashley's Book of Knots ISBN 0-385-04025-3

External references

• Grog's Animated Knots: How to tie the reef knot
• Ian's Shoelace Site: Reef Knot as applied to short shoelaces
• Notable Knot Index
• IGKT Sea Cadet Knots
• The Reef Knot Family