reef knot

Reef knot
Names	Reef knot, Square knot (from its appearance)
Category	Binding
Origin	Ancient
Related	Thief knot, Granny knot, Grief knot, Surgeon's 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	#74, #75, #460, #1204, #1402, #2573, #2574, #2577, #2580

The reef knot or square knot is an ancient and simple binding knot used to secure a rope or line around an object. Although the reef knot is often seen used for tying two ropes together, it is not recommended for this purpose due to potential instability of the knot.

A reef knot is formed by tying a left-handed overhand knot and then a right-handed overhand knot, or vice versa. 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". Two consecutive overhands of the same handedness will make a granny knot. The working ends of the reef knot must emerge both at the top or both at the bottom, otherwise a thief knot results.

Naming

The name "reef knot" dates from at least 1794^[1] and originates from its common use to reef sails,^[2] that is to tie part of the sail down to decrease its effective surface area in strong winds. To release the knot a sailor could collapse it with a pull of one hand; the sail's weight would make the collapsed knot come apart. It is specifically this behavior which makes the knot unsafe for connecting two ropes together.^[3]

The name "square knot" is found in Dana's 1841 maritime compendium A Seaman's Friend, which also gives "reef knot" as an alternate name.^[4][5]

Uses

Detail of Egyptian statue dating from 2350 BC depicting a reef knot securing a belt.

The reef knot is used to tie the two ends of a single line together such that they will secure something, for example a bundle of objects, that is unlikely to move much. The reef knot is also one of the key knots of macrame textiles.^[6]

In addition to its use by sailors, the knot lies flat when made with cloth and has been used for tying bandages for millennia. As a binding knot it was known to the ancient Greeks as the Hercules knot (Herakleotikon hamma) and is still used extensively in medicine.^[7] In his Natural History, Pliny relates the belief that wounds heal more quickly when bound with a "Hercules knot".^[8]

It has also been used since ancient times to tie belts and sashes. A modern use in this manner includes tying the obi (or belt) of a martial arts keikogi.

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 appropriate for tying plastic garbage or trash bags, as the knot forms a handle when tied in two twisted edges of the bag.

The reef knot figures prominently in Scouting worldwide. It is included in the international membership badge^[9] and many scouting awards.^[10] In the Boy Scouts of America demonstrating the proper tying of the square knot is a requirement for all boys joining the program.^[11]

Misuse as a bend

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

The reef knot's familiarity, ease of tying, and visually appealing symmetry belie its weakness. The International Guild of Knot Tyers warns that this knot should never be used to bend two ropes together.^[12] A proper bend knot, for instance a sheet bend or double fisherman's knot, should be used instead. Knotting authority Clifford Ashley claimed that misused reef knots have caused more deaths and injuries than all other knots combined.^[13] 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
Hercules Knot

See also

• Granny knot
• Thief knot
• Surgeon's knot
• List of bend knots
• List of binding knots
• List of knots
• Square knot (emblem or insignia)

Notes and references

External references

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