Author: Eggtimer

  • Transverse knot

    In mathematics, a transverse knot is a smooth embedding of a circle into a three-dimensional contact manifold such that the tangent vector at every point of the knot is transverse to the contact plane at that point.

    Any Legendrian knot can be C0-perturbed in a direction transverse to the contact planes to obtain a transverse knot. This yields a bijection between the set of isomorphism classes of transverse knots and the set of isomorphism classes of Legendrian knots modulo negative Legendrian stabilization.

    References

    • J. Epstein, D. Fuchs, and M. Meyer, Chekanov–Eliashberg invariants and transverse approximations of Legendrian knots, Pacific J. Math. 201 (2001), no. 1, 89–106.


    This article is adapted from “Transverse knot” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Figure-eight knot

    Figure-eight knot
    Figure-eight knot
    Names Figure-eight knot, figure-of-eight knot, Savoy knot, Flemish knot, double stopper
    Category Stopper
    Efficiency 80%
    Origin Ancient
    Related Stevedore knot, figure-eight loop, figure-eight follow through, directional figure eight
    Releasing Jamming
    Typical use General-purpose stopper knot. Replaces the common overhand knot in many uses.
    ABoK #420 #520 #570
    Conway Notation 2 2
    A/B notation 41
    Instructions

    The figure-eight knot or figure-of-eight knot is a type of stopper knot. It is very important in sailing, rock climbing and caving as a method of stopping ropes from running out of retaining devices. Like the overhand knot, which will jam under strain, often requiring the rope to be cut, the figure-eight will also jam, but is usually more easily undone than the overhand knot.

    Figure-eight knot
    When used as a stopper knot, the figure eight takes a more compact tightened form.

    The figure-eight or figure-of-eight knot is also called (in books) the Flemish knot. The name figure-of-eight knot appears in Lever’s Sheet Anchor; or, a Key to Rigging (London, 1808). The word “of” is nowadays usually omitted. The knot is the sailor’s common single-strand stopper knot and is tied in the ends of tackle falls and running rigging, unless the latter is fitted with monkey’s tails. It is used about ship wherever a temporary stopper knot is required. The figure-eight is much easier to untie than the overhand, it does not have the same tendency to jam and so injure the fiber, and is larger, stronger, and equally secure.

    The stevedore knot is an extension of simple figure-eight knot with an additional turn before the end is finally tightened.

    Different types

    Figure-eight loop

    The figure-eight loop is frequently used in climbing. It is the most common knot used to attach a rope to a harness, sometimes being described as the most important knot in the sport[2]. It forms a strong knot that’s relatively easy to tie, although can be difficult to untie after heavy loading.[3]

    Figure-eight bend

    The figure-eight bend knot is used to “splice” together two ropes, not necessarily of equal diameter. This knot is tied starting with a loose figure-eight knot on one rope (the larger-diameter one if unequal), and threading of the other rope’s running end through the first figure eight, starting at the first figure-eight’s running end and paralleling the path of the first rope through the figure eight until the second’s ropes running end lies parallel against the firsts standing end. The result is two figure-eight knots, each partly inside the other and tightening its hold on the other when they are pulled in opposite directions. This can be a permanent or temporary splice. While it precludes the ropes’ slipping relative to each other, it is a typical knot in having less strength than the straight ropes.

    Offset figure-eight bend

    The offset figure-eight bend is a poor knot that has been implicated in the deaths of several rock climbers.[4]

    Stein knot

    Figure-eight knot
    Stein knot

    The stein knot (also known as a stone knot) is a variation of the figure-eight knot. It is used to secure a rope that is already passed around a post or through a ring. It is quick and easy to tie and untie. It is a device rigging rather than a true knot. In canyoneering, it is used to isolate rope strands to allow one person to rappel while another is getting on the rappel, or allow rappellers the option of using a single or a double rope. It is also used in basketmaking.

    Symbolic use

    • In heraldry, this knot is known as Savoy knot.[5]
    • In the United States Navy, a figure-of-eight badge was formerly worn by enlisted men who had successfully completed the apprentice rating.[6]
    • In The Scout Association in the United Kingdom, awards for gallantry and long service are represented by a cloth figure-of-eight knot emblem in various colours.[7]

    See also

    References

    1. Ashley, Clifford W. (1944). The Ashley Book of Knots, p.85. Doubleday. ISBN 0-385-04025-3.
    2. “How to tie the perfect retraced figure 8”. Alpinesavvy. Retrieved 2026-07-18.
    3. “Climbing Knots for Beginners”. Berghaus. 2026-05-11. Retrieved 2026-07-18.
    4. Moyer, T. (2011). “Pull Tests of the ‘Euro Death-Knot’.
    5. Turner, John Christopher; Van de Griend, P C, eds. (1996). History and Science of Knots. Singapore: World Scientific Publishing Company. p. 390. ISBN 978-9810224691.
    6. Uniform Regulations: United States Navy. Washington: United States Navy Department. 1917. p. 62.
    7. Ford, Peter. “A guide to the Medals and Awards of The Scout Association (UK)” (PDF). heritage.scouts.org.uk. The Scouts Heritage Service. Retrieved 20 April 2020.

    Further reading

    • Adams, Colin C. (1994). The knot book: an elementary introduction to the mathematical theory of knots. W. H. Freeman.

    This article is adapted from “Figure-eight knot” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Transom knot

    Transom knot
    Transom knot
    Category Lashing
    Related Strangle knot, Constrictor knot, Square lashing
    Releasing Jamming
    Typical use Light-duty right-angle lashing
    ABoK #385, #1182, #1255, #3372

    The transom knot is a simple lashing knot used to secure two linear objects, such as spars, at right angles to each other.

    Relation to other knots

    While often described in relation to the constrictor knot, the underlying structure of the transom knot is the strangle knot.[1][2] The introduction of a second, perpendicular spar into a loose strangle knot tied around another spar will illustrate this point. In relation to the upper spar, the crossings of the knot come to very closely resemble those of a constrictor knot.

    Perhaps because of this Clifford Ashley described the transom knot as both “a modification of”[3] and “closely related to”[4] the constrictor knot. Despite these descriptions the transom knot is consistently illustrated in The Ashley Book of Knots as being based on a strangle knot.

    Use

    Suggested for binding kite sticks by Ashley,[5] it is useful generally as a light-duty or temporary square lashing. To reinforce, a second transom knot can be made on the opposite side and at a right-angle to the first.[2][5]

    References

    1. Budworth, Geoffrey (1985) [1983], The Knot Book, New York: Sterling Publishing, pp. 63–65
    2. 1 2 Warner, Charles (1992), A Fresh Approach to Knotting and Ropework, NSW, Australia, p. 83, ISBN 0-9592036-3-X{{citation}}: CS1 maint: location missing publisher (link)
    3. Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday, p. 62
    4. Ashley, p. 215
    5. 1 2 Ashley, p. 225

    This article is adapted from “Transom knot” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Fibered knot

    Fibered knot
    Figure-eight knot is fibered.

    In knot theory, a branch of mathematics, a knot or link K {\displaystyle K} {\displaystyle K}
    in the 3-dimensional sphere S 3 {\displaystyle S^{3}} {\displaystyle S^{3}} is called fibered or fibred (sometimes Neuwirth knot in older texts, after Lee Neuwirth) if there is a 1-parameter family F t {\displaystyle F_{t}} {\displaystyle F_{t}} of Seifert surfaces for K {\displaystyle K} {\displaystyle K}, where the parameter t {\displaystyle t} {\displaystyle t} runs through the points of the unit circle S 1 {\displaystyle S^{1}} {\displaystyle S^{1}}, such that if s {\displaystyle s} {\displaystyle s} is not equal to t {\displaystyle t} {\displaystyle t}
    then the intersection of F s {\displaystyle F_{s}} {\displaystyle F_{s}} and F t {\displaystyle F_{t}} {\displaystyle F_{t}} is exactly K {\displaystyle K} {\displaystyle K}.

    Examples

    Knots that are fibered

    For example:

    Knots that are not fibered

    Fibered knot
    The stevedore knot is not fibered

    The Alexander polynomial of a fibered knot is monic, i.e. the coefficients of the highest and lowest powers of t are plus or minus 1. Examples of knots with nonmonic Alexander polynomials abound, for example the twist knots have Alexander polynomials q t ( 2 q + 1 ) + q t 1 {\displaystyle qt-(2q+1)+qt^{-1}} {\displaystyle qt-(2q+1)+qt^{-1}}, where q is the number of half-twists.[1] In particular the stevedore knot is not fibered.

    Related constructions

    Fibered knots and links arise naturally, but not exclusively, in complex algebraic geometry. For instance, each singular point of a complex plane curve can be described
    topologically as the cone on a fibered knot or link called the link of the singularity. The trefoil knot is the link of the cusp singularity z 2 + w 3 {\displaystyle z^{2}+w^{3}} {\displaystyle z^{2}+w^{3}}; the Hopf link (oriented correctly) is the link of the node singularity z 2 + w 2 {\displaystyle z^{2}+w^{2}} {\displaystyle z^{2}+w^{2}}. In these cases, the family of Seifert surfaces is an aspect of the Milnor fibration of the singularity.

    A knot is fibered if and only if it is the binding of some open book decomposition of S 3 {\displaystyle S^{3}} {\displaystyle S^{3}}.

    See also

    References

    1. Fintushel, Ronald; Stern, Ronald J. (1998). “Knots, Links, and 4-Manifolds”. Inventiones Mathematicae. 134 (2): 363–400. arXiv:dg-ga/9612014. doi:10.1007/s002220050268. MR 1650308.

    External links


    This article is adapted from “Fibered knot” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Torus knot

    Torus knot
    the (2,−3)-torus knot, also known as the left-handed trefoil knot
    Torus knot
    (2,8) torus link with two components

    In knot theory, a torus knot is a special kind of knot that lies on the surface of an unknotted torus in R3. Similarly, a torus link is a link which lies on the surface of a torus in the same way. Each torus knot is specified by a pair of coprime integers p and q. A torus link arises if p and q are not coprime (in which case the number of components is gcd(p, q)). A torus knot is trivial (equivalent to the unknot) if and only if either p or q is equal to 1 or −1.

    The simplest nontrivial example is the (2,3)-torus knot, also known as the trefoil knot.

    Geometrical representation

    A torus knot can be rendered geometrically in multiple ways which are topologically equivalent (see Properties below) but geometrically distinct. The convention used in this article and its figures is the following.

    The (p,q)-torus knot winds q times around a circle in the interior of the torus, and p times around its axis of rotational symmetry.[note 1]. If p and q are not relatively prime, then we have a torus link with more than one component.

    The direction in which the strands of the knot wrap around the torus is also subject to differing conventions. The most common is to have the strands form a right-handed screw for p q > 0.[3][4][5]

    The (p,q)-torus knot can be given by the parametrization

    x = r cos ( p ϕ ) y = r sin ( p ϕ ) z = sin ( q ϕ ) {\displaystyle {\begin{aligned}x&=r\cos(p\phi )\\y&=r\sin(p\phi )\\z&=-\sin(q\phi )\end{aligned}}} {\displaystyle {\begin{aligned}x&=r\cos(p\phi )\\y&=r\sin(p\phi )\\z&=-\sin(q\phi )\end{aligned}}}

    where r = cos ( q ϕ ) + 2 {\displaystyle r=\cos(q\phi )+2} {\displaystyle r=\cos(q\phi )+2} and 0 < ϕ < 2 π {\displaystyle 0<\phi <2\pi } {\displaystyle 0<\phi <2\pi }. This lies on the surface of the torus given by ( r 2 ) 2 + z 2 = 1 {\displaystyle (r-2)^{2}+z^{2}=1} {\displaystyle (r-2)^{2}+z^{2}=1} (in cylindrical coordinates).

    Other parameterizations are also possible, because knots are defined up to continuous deformation. The illustrations for the (2,3)- and (3,8)-torus knots can be obtained by taking r = cos ( q ϕ ) + 4 {\displaystyle r=\cos(q\phi )+4} {\displaystyle r=\cos(q\phi )+4}, and in the case of the (2,3)-torus knot by furthermore subtracting respectively 3 cos ( ( p q ) ϕ ) {\displaystyle 3\cos((p-q)\phi )} {\displaystyle 3\cos((p-q)\phi )} and 3 sin ( ( p q ) ϕ ) {\displaystyle 3\sin((p-q)\phi )} {\displaystyle 3\sin((p-q)\phi )} from the above parameterizations of x and y. The latter generalizes smoothly to any coprime p,q satisfying p < q < 2 p {\displaystyle p<q<2p} {\displaystyle p<q<2p}.

    Properties

    Torus knot
    A (3,−7)-3D torus knot.

    A torus knot is trivial if and only if either p or q is equal to 1 or −1.[4][5]

    Each nontrivial torus knot is prime[6] and chiral.[4]

    The (p,q) torus knot is equivalent to the (q,p) torus knot.[3][5][7] The (p,−q) torus knot is the obverse (mirror image) of the (p,q) torus knot.[5] The (−p,−q) torus knot is equivalent to the (p,q) torus knot except for the reversed orientation.

    Torus knot
    The (3, 4) torus knot on the unwrapped torus surface, and its braid word

    Any (p,q)-torus knot can be made from a closed braid with p strands. The appropriate braid word is [8]

    ( σ 1 σ 2 σ p 1 ) q . {\displaystyle (\sigma _{1}\sigma _{2}\cdots \sigma _{p-1})^{q}.} {\displaystyle (\sigma _{1}\sigma _{2}\cdots \sigma _{p-1})^{q}.}

    (This formula assumes the common convention that braid generators are right twists,[4][8][9][10] which is not followed by the Wikipedia page on braids.)

    The crossing number of a (p,q) torus knot with p,q > 0 is given by

    c = min((p1)q, (q1)p).

    The genus of a torus knot with p,q > 0 is

    g = 1 2 ( p 1 ) ( q 1 ) . {\displaystyle g={\frac {1}{2}}(p-1)(q-1).} {\displaystyle g={\frac {1}{2}}(p-1)(q-1).}

    The Alexander polynomial of a torus knot is [3][8]

    t k ( t p q 1 ) ( t 1 ) ( t p 1 ) ( t q 1 ) , {\displaystyle t^{k}{\frac {(t^{pq}-1)(t-1)}{(t^{p}-1)(t^{q}-1)}},} {\displaystyle t^{k}{\frac {(t^{pq}-1)(t-1)}{(t^{p}-1)(t^{q}-1)}},} where k = ( p 1 ) ( q 1 ) 2 . {\displaystyle k=-{\frac {(p-1)(q-1)}{2}}.} {\displaystyle k=-{\frac {(p-1)(q-1)}{2}}.}

    The Jones polynomial of a (right-handed) torus knot is given by

    t ( p 1 ) ( q 1 ) / 2 1 t p + 1 t q + 1 + t p + q 1 t 2 . {\displaystyle t^{(p-1)(q-1)/2}{\frac {1-t^{p+1}-t^{q+1}+t^{p+q}}{1-t^{2}}}.} {\displaystyle t^{(p-1)(q-1)/2}{\frac {1-t^{p+1}-t^{q+1}+t^{p+q}}{1-t^{2}}}.}

    The complement of a torus knot in the 3-sphere is a Seifert-fibered manifold, fibred over the disc with two singular fibres.

    Let Y be the p-fold dunce cap with a disk removed from the interior, Z be the q-fold dunce cap with a disk removed from its interior, and X be the quotient space obtained by identifying Y and Z along their boundary circle. The knot complement of the (p, q) -torus knot deformation retracts to the space X. Therefore, the knot group of a torus knot has the presentation

    x , y x p = y q . {\displaystyle \langle x,y\mid x^{p}=y^{q}\rangle .} {\displaystyle \langle x,y\mid x^{p}=y^{q}\rangle .}

    Torus knots are the only knots whose knot groups have nontrivial center (which is infinite cyclic, generated by the element x p = y q {\displaystyle x^{p}=y^{q}} {\displaystyle x^{p}=y^{q}} in the presentation above).

    The stretch factor of the (p,q) torus knot, as a curve in Euclidean space, is Ω(min(p,q)), so torus knots have unbounded stretch factors. Undergraduate researcher John Pardon won the 2012 Morgan Prize for his research proving this result, which solved a problem originally posed by Mikhail Gromov.[11][12]

    Connection to complex hypersurfaces

    Torus knot
    EureleA Award showing a (2,3)-torus knot.

    The (p,q)torus knots arise when considering the link of an isolated complex hypersurface singularity. One intersects the complex hypersurface with a hypersphere, centred at the isolated singular point, and with sufficiently small radius so that it does not enclose, nor encounter, any other singular points. The intersection gives a submanifold of the hypersphere.

    Let p and q be coprime integers, greater than or equal to two. Consider the holomorphic function f : C 2 C {\displaystyle f:\mathbb {C} ^{2}\to \mathbb {C} } {\displaystyle f:\mathbb {C} ^{2}\to \mathbb {C} } given by f ( w , z ) := w p + z q . {\displaystyle f(w,z):=w^{p}+z^{q}.} {\displaystyle f(w,z):=w^{p}+z^{q}.} Let V f C 2 {\displaystyle V_{f}\subset \mathbb {C} ^{2}} {\displaystyle V_{f}\subset \mathbb {C} ^{2}} be the set of ( w , z ) C 2 {\displaystyle (w,z)\in \mathbb {C} ^{2}} {\displaystyle (w,z)\in \mathbb {C} ^{2}} such that f ( w , z ) = 0. {\displaystyle f(w,z)=0.} {\displaystyle f(w,z)=0.} Given a real number 0 < ε 1 , {\displaystyle 0<\varepsilon \ll 1,} {\displaystyle 0<\varepsilon \ll 1,} we define the real three-sphere S ε 3 R 4 C 2 {\displaystyle \mathbb {S} _{\varepsilon }^{3}\subset \mathbb {R} ^{4}\hookrightarrow \mathbb {C} ^{2}} {\displaystyle \mathbb {S} _{\varepsilon }^{3}\subset \mathbb {R} ^{4}\hookrightarrow \mathbb {C} ^{2}} as given by | w | 2 + | z | 2 = ε 2 . {\displaystyle |w|^{2}+|z|^{2}=\varepsilon ^{2}.} {\displaystyle |w|^{2}+|z|^{2}=\varepsilon ^{2}.} The function f {\displaystyle f} {\displaystyle f} has an isolated critical point at ( 0 , 0 ) C 2 {\displaystyle (0,0)\in \mathbb {C} ^{2}} {\displaystyle (0,0)\in \mathbb {C} ^{2}} since f / w = f / z = 0 {\displaystyle \partial f/\partial w=\partial f/\partial z=0} {\displaystyle \partial f/\partial w=\partial f/\partial z=0} if and only if w = z = 0. {\displaystyle w=z=0.} {\displaystyle w=z=0.} Thus, we consider the structure of V f {\displaystyle V_{f}} {\displaystyle V_{f}} close to ( 0 , 0 ) C 2 . {\displaystyle (0,0)\in \mathbb {C} ^{2}.} {\displaystyle (0,0)\in \mathbb {C} ^{2}.} In order to do this, we consider the intersection V f S ε 3 S ε 3 . {\displaystyle V_{f}\cap \mathbb {S} _{\varepsilon }^{3}\subset \mathbb {S} _{\varepsilon }^{3}.} {\displaystyle V_{f}\cap \mathbb {S} _{\varepsilon }^{3}\subset \mathbb {S} _{\varepsilon }^{3}.} This intersection is the so-called link of the singularity f ( w , z ) = w p + z q . {\displaystyle f(w,z)=w^{p}+z^{q}.} {\displaystyle f(w,z)=w^{p}+z^{q}.} The link of f ( w , z ) = w p + z q {\displaystyle f(w,z)=w^{p}+z^{q}} {\displaystyle f(w,z)=w^{p}+z^{q}}, where p and q are coprime, and both greater than or equal to two, is exactly the (p,q)torus knot.[13]

    List

    Table
    #
    A-B Image P Q Cross
    #
    0 01 Torus knot 1 0 0
    3a1 31 Torus knot 2 3 3
    5a2 51 Torus knot 2 5 5
    7a7 71 Torus knot 2 7 7
    8n3 819 Torus knot 3 4 8
    9a41 91 Torus knot 2 9 9
    10n21 10124 Torus knot 3 5 10
    11a367 Torus knot 2 11 11
    13a4878 Torus knot 2 13 13
    14n21881 Torus knot 3 7 14
    15n41185 Torus knot 4 5 15
    15a85263 Torus knot 2 15 15
    16n783154 Torus knot 3 8 16
    Torus knot 2 17 17
    Torus knot 2 19 19
    Torus knot 3 10 20
    Torus knot 4 7 21
    Torus knot 2 21 21
    Torus knot 3 11 22
    Torus knot 2 23 23
    Torus knot 5 6 24
    Torus knot 2 25 25
    Torus knot 3 13 26
    Torus knot 4 9 27
    Torus knot 2 27 27
    Torus knot 5 7 28
    Torus knot 3 14 28
    Torus knot 2 29 29
    Torus knot 2 31 31
    Torus knot 5 8 32
    Torus knot 3 16 32
    Torus knot 4 11 33
    Torus knot 2 33 33
    Torus knot 3 17 34
    Torus knot 6 7 35
    Torus knot 2 35 35
    Torus knot 5 9 36
    Torus knot 7 8 48
    Torus knot 7 9 54
    Torus knot 8 9 63

    g-torus knot

    A g-torus knot is a closed curve drawn on a g-torus. More technically, it is the homeomorphic image of a circle in which can be realized as a subset of a genus g handlebody in (whose complement is also a genus g handlebody). If a link is a subset of a genus two handlebody, it is a double torus link.[14]

    For genus two, the simplest example of a double torus knot that is not a torus knot is the figure-eight knot.[15][16]

    Notes

    1. Note that this use of the roles of p and q is contrary to what appears on.[1] It is also inconsistent with the pictures that appear in: [2]

    See also

    References

    1. Torus Knot on Wolfram Mathworld .
    2. “36 Torus Knots”, The Knot Atlas. .
    3. 1 2 3 Livingston, Charles (1993). Knot Theory. Mathematical Association of America. p. . ISBN 0-88385-027-3.
    4. 1 2 3 4 Murasugi, Kunio (1996). Knot Theory and its Applications. Birkhäuser. p. . ISBN 3-7643-3817-2.
    5. 1 2 3 4 Kawauchi, Akio (1996). A Survey of Knot Theory. Birkhäuser. p. . ISBN 3-7643-5124-1.
    6. Norwood, F. H. (1982-01-01). “Every two-generator knot is prime”. Proceedings of the American Mathematical Society. 86 (1): 143–147. doi:10.1090/S0002-9939-1982-0663884-7. ISSN 0002-9939. JSTOR 2044414.
    7. Baker, Kenneth (2011-03-28). “p q is q p”. Sketches of Topology. Retrieved 2020-11-09.
    8. 1 2 3 Lickorish, W. B. R. (1997). An Introduction to Knot Theory. Springer. p. . ISBN 0-387-98254-X.
    9. Dehornoy, P.; Dynnikov, Ivan; Rolfsen, Dale; Wiest, Bert (2000). Why are Braids Orderable? (PDF). p. . Archived from the original (PDF) on 2012-04-15. Retrieved 2011-11-12.
    10. Birman, J. S.; Brendle, T. E. (2005). “Braids: a Survey”. In Menasco, W.; Thistlethwaite, M. (eds.). Handbook of Knot Theory. Elsevier. p. . ISBN 0-444-51452-X.
    11. Kehoe, Elaine (April 2012), “2012 Morgan Prize”, Notices of the American Mathematical Society, vol. 59, no. 4, pp. 569–571, doi:10.1090/noti825.
    12. Pardon, John (2011), “On the distortion of knots on embedded surfaces”, Annals of Mathematics, Second Series, 174 (1): 637–646, arXiv:1010.1972, doi:10.4007/annals.2011.174.1.21, MR 2811613, S2CID 55567836
    13. Milnor, J. (1968). Singular Points of Complex Hypersurfaces. Princeton University Press. p. . ISBN 0-691-08065-8.
    14. Rolfsen, Dale (1976). Knots and Links. Publish or Perish, Inc. p. . ISBN 0-914098-16-0.
    15. Hill, Peter (December 1999). “On Double-Torus Knots (I)”. Journal of Knot Theory and Its Ramifications. 08 (8): 1009–1048. doi:10.1142/S0218216599000651. ISSN 0218-2165.
    16. Norwood, Frederick (November 1989). “Curves on surfaces”. Topology and Its Applications. 33 (3): 241–246. doi:10.1016/0166-8641(89)90105-3.

    External links


    This article is adapted from “Torus knot” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Fiador knot

    Fiador knot
    Fiador knot
    Names Fiador knot, Ole fiador knot, Theodore knot, Hackamore diamond knot
    Category Loop
    Related Bottle sling, Diamond knot
    Typical use rope halters, hackamores, and hobbles
    ABoK #1110, #2569

    The fiador knot (also Theodore knot) is a decorative, symmetrical knot used in equine applications to create items such as rope halters, hobbles, and components of the fiador on some hackamore designs. As traditionally described, it is a four strand diamond knot in which six of the eight ends loop back into the knot, thus allowing it to be tied with a single line.[1] While a specific knot is discussed in this article, the fiador knot has also been treated as an entire class of multi-strand knots similarly made with a single line.[2][3]

    Etymology

    The origin of the variant name “Theodore knot”, used in the United States, is a corruption of the Spanish fiador. American cowboys likewise corrupted a number of other closely related terms, substituting “hackamore” for jaquima and “McCarty” for mecate.[4]

    Knotting authority Clifford Ashley relates Philip Ashton Rollins’s suggestion that, “When Theodore Roosevelt, ‘the hero of San Juan Hill,’ visited the Southwest, shortly after the Spanish–American War, it was a foregone conclusion that the Spanish name ‘Fiador’ would be corrupted to ‘Theodore’ in his honor.”[1]

    Tying

    Considered a difficult knot to tie, cowboys were said to have been able to collect a fee for tying it.[5] Ashley went so far as to include it in a chapter covering trick knots in The Ashley Book of Knots stating archly, “the trick is to succeed in tying it.”[6]

    Many methods have been devised to tie the fiador knot,[7] including fixtures used to hold the parts in shape while tying.[4][8] More recent sources have shown a simpler method of forming the fiador knot using a flat precursor knot.[9][10][11]

    The following images show a method for tying the fiador knot:

    • Fiador knot
    • Fiador knot
    • Fiador knot
    • Fiador knot

    Tight face and loose face

    Careful inspection reveals the two faces of the completed fiador knot, where the four strands emerge, are not identical. One has the appearance of a crown knot surrounding the emerging strands and is somewhat resistant to spreading when they are pulled apart. By comparison, the strands emerging from the other face of the knot are not nearly as well-contained and if pulled apart, the fiador knot easily distorts and splays. Depending on how the fiador knot is tied, these distinct faces can be positioned differently with respect to the side of the knot with the two loops and the side with a single loop and the two free ends.

    While most sources fail to discuss and differentiate the two faces, those that do suggest the tight face is best oriented towards single loop and two free ends if the knot is to be used in a rope fiador.[10][12] The rationale stated is that the single loop and free end side of the knot will be subject to more spreading when it passed around the neck of the horse. By contrast, the strands on the two-loop side of the fiador knot will generally be kept together by the double hackamore knot immediately below it.[13][14]

    Regardless of the original tying method, the orientation of the tight and loose faces can be swapped in the completed knot.[11] By loosening the fiador knot, the tight face can be pressed towards, over, and around the rest of the knot. The knot will invert, “much the same as a mitten is turned inside out.”[15] When retightened, the tight and loose faces will have been exchanged.

    Uses by equestrians

    Fiador knot
    A mockup of the three knots used on a hackamore’s fiador with the fiador knot in the center.

    There are several ways the fiador knot is used with certain types of horse tack:

    • The knot is used on, and shares its name with, the fiador of a hackamore.[16] The fiador knot holds the four strands of the fiador together under the horse’s jaw, while a doubled bottle sling—sometimes called a “hackamore knot” in this context—is used to attach the fiador to the heel knot of the bosal, or noseband, of the hackamore. A becket hitch is used to secure the fiador around the throatlatch of the horse.[3] In North America, again according to Ashley, “…the method originated in the South American pampas and worked its way, via Mexico, to the Southwestern cow country, arriving there soon after the conclusion of the Spanish–American War.”[1]
    • On knotted rope halters, the knot often is used under the jaw both as a decorative knot, and also to fashion the lower loop onto which a lead rope is attached. On a rope halter, the fiador knot is made from one continuous piece of rope, and is, along with a series of double overhand knots, one of two types of knots that comprise most rope halters.
    • For one style of rope hobbles, a brass ring may be attached to the double loops on one side of the knot to join the hobble for the horse’s other front foot. On the other side, a diamond knot terminates the two loose ends and the single loop is placed over this to encircle the horse’s fetlock. A small rope slide (melted with a solder iron) on this single loop is pushed against the diamond knot to prevent the loop from slipping off the foot.

    See also

    Notes and references

    1. 1 2 3 Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday, pp. 43 & 201
    2. Schaake, A.G.; Turner, J.C.; Sedgwick, D.A. (1990), Braiding – Regular Fiador Knots, A Series of Books on Braiding, vol. 2/1, Hamilton, NZ: University of Waikato, ISBN 0-908830-02-5
    3. 1 2 Hall, Tom (July 1996). “Fiador Knots”. Knotting Matters (53). London: International Guild of Knot Tyers: 13–24. ISSN 0959-2881.
    4. 1 2 Grant, Bruce (2004) [1972], Encyclopedia of Rawhide and Leather Braiding, Atglen, Pennsylvania: Cornell Maritime Press, pp. 144–149
    5. Day, Cyrus L. (1967), Quipus and Witches’ Knots, Lawrence: University of Kansas Press, p. 90
    6. Ashley, p. 413
    7. Ulrich, Eugene (1986), The Hackamore Diamond Knot: Four Methods of Tying – Plus the Knot in a Bottle, Faith, SD: Owl Printers
    8. https://www.youtube.com/channel/UCC_NnpECflp70GolC47BGoQ/videos Antonio Marin’s YouTube account that shows at least 5 methods of tying the fiador knot (in Spanish, 2 colors in the ropes)
    9. Ulrich(1986), p. 32
    10. 1 2 Longanecker, Diane (2009), Halter-tying Success (2nd ed.), Dayton, Washington: Horse Owner Success Books, pp. 60–75, ISBN 978-0-9635320-7-7
    11. 1 2 Budworth, Geoffrey (December 2005). “The Fiador Knot”. Knotting Matters (89). London: International Guild of Knot Tyers: 34–36. ISSN 0959-2881.
    12. All photos on this page show the completed knot in this configuration.
    13. Ulrich(1986), pp. 3–4
    14. Schaake, et al.(1990), pp. 8 & 15
    15. Ulrich(1986), p. 25
    16. Grant, Bruce and Rice, Lee. How to Make Cowboy Horse Gear Cornell Maritime Press; 2nd edition (June 1956), ISBN 0-87033-034-9, ISBN 978-0-87033-034-6

    External links


    This article is adapted from “Fiador knot” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Tom fool’s knot

    Tom fool’s knot
    Tom fool's knot
    Names Tom fool’s knot, Tom fool knot, Conjurer’s knot, Bow knot
    Category Trick
    Related Handcuff knot, Sheepshank, Fireman’s chair knot
    ABoK #1141, #2290, #2291, #2534

    The Tom fool’s knot, also called the conjurer’s knot or bow knot, is sometimes considered a handcuff knot but is somewhat inferior for this purpose to the knot which usually bears that name.[1]:208 It is a good knot with which to commence a slightly fancy sheepshank.[1]:210 It is also used as a trick knot due to the speed with which it can be made.[1]:406

    History

    Tom fool’s knot is believed to be the knot epankylotos brokhos described by the 1st Century Greek physician Heraklas.[2]

    Tying

    It is formed by making two loops, not exactly overlaying each other. The inner half of each hitch or loop is pulled under and through the outer side of the opposite loop.

    See also

    References

    1. 1 2 3 Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday
    2. Hage, J. Joris (2008). “Heraklas on Knots: Sixteen Surgical Nooses and Knots from the First Century A.D.”. World Journal of Surgery. 32 (4): 648–655. doi:10.1007/s00268-007-9359-x. PMID 18224483. S2CID 21340612.

    External links

    • Ian Knot, shoelace knot based on Tom fool’s knot


    This article is adapted from “Tom fool's knot” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Farrimond friction hitch

    Farrimond Friction Hitch
    Farrimond friction hitch
    Category Hitch
    Origin Barry Farrimond MBE 2008
    Related Taut-line hitch, Prusik knot, Siberian hitch
    Releasing Quick release
    Typical use Camping, Adjusting line tension

    The Farrimond friction hitch is a quick release adjustable friction hitch for use on lines under tension. It is useful when the length of a line will need to be periodically adjusted in order to maintain or adjust tension whilst remaining quick and easy to untie; such as when hanging the ridge line for a Basha. It can be used in very effective conjunction with the Siberian hitch for this purpose. It can also be used as a mooring knot.

    History

    The first known presentation of this knot was made by British actor Barry Farrimond MBE in 2008 during a demonstration at the Yellow Wood Bush Camp, Wales.

    Tying

    The diagram below is shown from a birds eye perspective with the green dot representing a fixed point such as a tree or post which a ridge line might be attached to. After passing the working end around the back of this fixed point, create a loop that is then placed on top of the ridge line as in fig 1. Once this has been done take the loop and wrap it around the ridge line (following the directions shown by the red arrows) until you reach fig 4. Next take the working end of the rope and create a bight in it. Follow the red arrow in fig 4 which shows the bight being passed under and through the hoop of rope to form the knot’s quick release mechanism. Once the knot has been tightened up it should be able to resist considerable load on the ridge line whilst remaining easy to adjust and quick to release.

    Farrimond friction hitch

    See also

    References

    External links


    This article is adapted from “Farrimond friction hitch” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Farmer’s loop

    Farmer’s loop
    Farmer's loop
    Names Farmer’s loop, Wireman’s knot[1]
    Category Loop
    Related Alpine butterfly knot, Artillery loop, Span loop
    Releasing Non-jamming
    Typical use Climbing, agriculture
    ABoK #1054, #1056, #2565

    The farmer’s loop is a knot which forms a fixed loop.[2] As a midline loop knot made with a bight, it is related to several other similar knots, including the alpine butterfly knot and artillery loop.

    If pulled with one hand holding one end, the other hand holding the start side of the loop that is the continuation of the same end, before tightening the knot of the loop, it may capsize to a slip knot with a complicated and heavy knot.

    It is tied on one hand to make a loop about twice the size of that hand (use fingers for a smaller one, thumb-hook-to-elbow for a large one), as follows:[3][4][5]

    1. start with the rope 3 times around the palm of one hand, let the ends hang down,
    2. then pull the initial middle turn up from the top edge and place it over to the right (of the right loops top edge)
    3. then pull the now new middle turn up from the top edge and place it over to the left
    4. then pull the now new middle turn up from the top edge and place it over to the right
    5. then pull the now new middle turn up to form the loop, dress and tighten before use

    The knot is a good one on all three counts—lead, security, and strength. Moreover, the method of tying is both ingenious and distinctive, and once mastered, it is not apt to be forgotten.

    To tie: Take three turns around the left arm or hand, according to the size of the material being used. Move the center turn to the outside three times, as indicated by the arrows, first right, then left, and finally right again. Finally, pull out (extend) the center turn, and the knot is ready for use.

    History

    Cornell University professor Howard W. Riley published this knot in an agricultural extension pamphlet devoted to farming knots in 1912.[2] He was shown the knot by a farmer at the 1910 Genesee County Fair in Batavia, New York. Riley noted that he had never seen the knot described in any reference book.[6]

    See also

    References

    1. Department of the Army (2002), Field Manual No. 3-97.61 Military Mountaineering, Washington, D.C.: United States Government, p. 4.16
    2. 1 2 3 Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday, p. 191
    3. Richard McLeod (2017-02-10). Farmer’s Loop. Retrieved 2024-09-05 via YouTube.
    4. SebringSage (2014-10-09). Knot Tying: The Farmer’s Loop. Retrieved 2024-09-05 via YouTube.
    5. “- YouTube”. www.youtube.com. Retrieved 2024-09-05.
    6. Riley, Howard W. (January 1912). “Knots, Hitches, and Splices”. The Cornell Reading-Courses. Rural Engineering Series No. 1. 1 (8). Ithaca, NY: New York State College of Agriculture at Cornell University: 1438. Retrieved 2011-11-08. As collected in Documents of the Assembly of the State of New York, 136th Session, 1913, Vol. 19, No. 29, Part 5.

    External links


    This article is adapted from “Farmer's loop” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.

  • Timber hitch

    Timber hitch
    Timber hitch
    Names Timber hitch, Fig.8 Timber Hitch, Bowyer’s Knot, Lumberman’s Knot, Countryman’s Knot
    Category Hitch
    Related Killick hitch
    Releasing Non-jamming
    ABoK #1668,#195, #479, #1665, #2161
    Instructions

    The timber hitch is a knot used to attach a single length of rope to a cylindrical object. Secure while tension is maintained, it is easily untied even after heavy loading.[1][2][3]

    The timber hitch is a very old knot. It is first known to have been mentioned in a nautical source c. 1625[4] and illustrated in 1762.[1]

    Usage

    As the name suggests, this knot is often used by lumbermen and arborists for attaching ropes or chains to tree trunks, branches, and logs.[3][5] For stability when towing or lowering long items, the addition of a half-hitch in front of the timber hitch creates a timber hitch and a half hitch,[6] or known as a killick hitch[2] when at sea.[7] A killick is “a small anchor or weight for mooring a boat, sometimes consisting of a stone secured by pieces of wood”.[8] This can also prevent the timber hitch from rolling.[3] The timber hitch is one of the few knots that can easily be tied in a chain, leading to its use in applications where ropes lack the necessary strength and would break under the same amount of tension.

    Timber hitch

    The Timber Hitch is very convenient for hoisting boards and timbers, as it cannot jam and may be instantly loosened. If timber is to be hoisted on end the Timber Hitch is made with the end of the rope below the center of the timber and then a Half Hitch is added in the standing part at the upper end of the timber.

    Clifford W. Ashley, The Ashley Book of Knots, Entry 195.

    This knot is also known as the Bowyer’s Knot, as it is used to attach the lower end of the bowstring to the bottom limb on an English longbow.[9]

    The hitch is also one of the methods used to connect ukulele[10] and classical guitar[11][12] strings to the bridge of the instruments.

    • Timber hitch on a tree trunk.
      Timber hitch on a tree trunk.
    • Timber hitches on the bridge of a classical guitar
      Timber hitches on the bridge of a classical guitar

    Tying

    To make the knot, pass the rope completely around the object. Pass the running end around the standing part, then through the loop just formed. Make three or more turns (or twists) around the working part. Pull on the standing part to tighten around the object.

    A common error in tying can be avoided by assuring that the turns are made in the working part around itself.[13] When making the hitch in laid rope, the turns should be made with the lay of the rope, that is, in the same direction as the twist of the rope.[1][2]

    • Timber hitch step by step. Three turns are shown.
      Timber hitch step by step. Three turns are shown.
    • Tying technique for stringed instruments
      Tying technique for stringed instruments

    Security

    Although The Ashley Book of Knots states that “three tucks or turns are ample”,[1] this work was written prior to the wide use of synthetic fiber cordage. Later sources suggest five or more turns may be required for full security in modern synthetic ropes.[3][14]

    ABoK Context

    Comparison of 3 types of Half Hitches, and then Timber Hitches, including Killik conversion for errant angle of pull.
    Comparison of 3 types of Half Hitches, and then Timber Hitches, including Killik conversion for errant angle of pull.

    The Timber Hitches list almost immediately in “CHAPTER 21: HITCHES TO SPAR AND RAIL (RIGHT-ANGLE PULL)”, only preceded there by 3 Half Hitch base forms. The context begins with typical Half Hitch#1662 as worst security/nip warnings warning with Skull/Crossbones, but a base structure to build on. Then shows the most security at top nip/opposing the linear load pull position as a safer Half Hitch form#1663 awarding Anchor icon if constant pull. Then introduces Timber Hitch #1665 concept from extension of worst nip Half Hitch tail#1662 . #1666 then shows Fig.8 concept as upgrade to Half Hitch#1662 and shows the nip position pushed to halfway between normal and top nip Half Hitch. Also adds a geometric consideration of:”particularly if the encompassed object is small.” of even higher nip. #1668 then shows the Fig.8 Timber Hitch with nip more to side and not bottom as improvement.[1]

    Next trick is in #1669 Fig.8 Hitch with Round Turn. Where the Round Turn is around the Standing Part and Fig.8 portion actually pictured as fig.8 Timber Hitch and so adds that the “Round Turn on the Standing Part adds materially to the strength of the knot.”[1]

    Next chapter is “CHAPTER 22: HITCHES TO MASTS, RIGGING, AND CABLE (LENGTHWISE PULL) To withstand a lengthwise pull without slipping is about the most that can be asked of a hitch. Great care must be exercised in tying the following series of knots, and the impossible must not be expected” that starts off with a Timber Hitch preceded by ‘lengthwise’ Half Hitch form to convert Timber from “RIGHT-ANGLE PULL” to “LENGTHWISE PULL” usage in the back to back chapters.[1]

    See also

    References

    1. 1 2 3 4 5 6 7 Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday, p. 290
    2. 1 2 3 Day, Cyrus Lawrence (1986), The Art of Knotting and Splicing (4th ed.), Annapolis: Naval Institute Press, pp. 94–95
    3. 1 2 3 4 Jepson, Jeff (2000), The Tree Climber’s Companion (2nd ed.), Minneapolis: Beaver Tree Publishing, p. 78
    4. Anderson, R.C.; Salisbury, W., eds. (1958), A Treatise on Rigging c. 1625, Occasional Publications No. 6, London: The Society for Nautical Research, p. 51, The Truss is fastened to the middle of the mayne yearde betwene the Parell with a tymber hitch and from thence goes through a blocke fastened to the mayne mast close to the middle decke and so to the Capstone when you will use him.
    5. Ashley (1944), p. 77
    6. Blandford, Percy (1965), Knots and Splices, New York, New York, USA: Arco Publishing Company, Inc, p. 23
    7. Blandford, Percy (1965), Knots and Splices, New York, New York, USA: Arco Publishing Company, Inc, p. 32
    8. “Killick”.
    9. Bickerstaffe, Pip (2010). “Tying the Bowyers Knot”. Grand Affairs Group. Archived from the original on 2012-04-26. Retrieved 2012-01-02.
    10. Wood, Alistair (2011), Ukulele For Dummies, Chichester, England: John Wiley & Sons, pp. 269–271
    11. Cumpiano, William R.; Natelson, Jonathan D. (1997), Guitarmaking, Tradition and Technology, San Francisco: Chronicle Books, pp. 368–369
    12. Pinksterboer, Hugo (2001), Tipbook Acoustic Guitar, Netherlands: The Tipbook Company, pp. 66–69
    13. Asher, Harry (1989), The Alternative Knot Book, London: Nautical Books, p. 32, ISBN 0-7136-5950-5
    14. Budworth, Geoffrey (1997), The Complete Book of Knots, New York, New York: Lyons & Burford, p. 47

    External links


    This article is adapted from “Timber hitch” on Wikipedia, written by its contributors, and used under CC BY-SA 4.0. Text on this page is available under the same licence. Source snapshot: Wikipedia via Kiwix, 2026-07-20.