The underwriter's knot is used in
electrical wiring
Electrical wiring is an electrical installation of Electrical cable, cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure.
Wiring is subject to safety standards for design and in ...
as
strain relief
Cable management refers to management of electrical cable, electrical or optical cable in a Enclosure (electrical), cabinet or an installation. The term is used for products, workmanship or planning.
Cables can easily become tangled, making ...
to prevent a
cable
Cable may refer to:
Mechanical
* Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof
* Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...
from being pulled from
electrical terminals when the cable is yanked.
History
Clifford Ashley listed it as an electrician's knot in 1944. He suggested it be used "where rough treatment is expected" and described it as a two-strand
wall knot.
The name may come from its use by fire underwriters, who understood its importance in the prevention of both electrocution and fire.
Function
The knot is typically used as a
stopper knot
A stopper knot (or simply stopper) is a knot that creates a fixed thicker point on an otherwise-uniform thickness rope for the purpose of preventing the rope, at that point, from slipping through a narrow passage, such as a hole in a block. To pa ...
where a lamp or appliance cord passes through a hole or slot of a plug or socket. Its purpose is to "reduce strain on the screw terminal connections—where the metal parts of the wires connect to the socket or plug—and prevent the wires from pulling free."
See also
*
List of knots
This list of knots includes many alternative names for common knots and lashings. Knot names have evolved over time, and there are many conflicting or confusing naming issues. The overhand knot, for example, is also known as the thumb knot. The ...
References
External links
How to tie an Underwriter's Knot. ''Animated Knots.''
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Double knots
Cables