Gender of connectors and fasteners - Wikipedia

Jump to content

Search

Search

Donate

Create account

Log in

Personal tools

Donate

Create account

Log in

Gender of connectors and fasteners

3 languages

فارسی<br>Nederlands<br>Српски / srpski

Edit links

From Wikipedia, the free encyclopedia

Engineering designation

This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.<br>Find sources: "Gender of connectors and fasteners" – news · newspapers · books · scholar · JSTOR (January 2013) (Learn how and when to remove this message)

Schematic symbols for male and female connector pins<br>In electrical and mechanical trades and manufacturing, each half of a pair of mating connectors or fasteners is conventionally designated as male or female ,[1] a distinction referred to as its gender .[2] The female connector is generally a receptacle that receives and holds the male connector. Alternative terms such as plug and socket or jack are sometimes used, particularly for electrical connectors.[3]

The assignment is a direct analogy with male and female genitalia. The part bearing one or more protrusions, or which fits inside the other, is designated male, while the one with the corresponding indentations, or fitting outside the other, is designated female. Extension of the analogy results in the verb to mate being used to describe the process of connecting two corresponding parts together.

In some cases (notably electrical power connectors), the gender of connectors is selected according to rigid rules which enforce a sense of one-way directionality (e.g. a flow of power from one device to another). This is done to enhance safety, or ensure proper functionality, by preventing unsafe or non-functional configurations from being set up.

In terms of mathematical graph theory, an electrical power distribution network made up of plugs and sockets is a directed tree, with the directionality arrows corresponding to the female-to-male transfer of electrical power through each mated connection. This is an example where male and female connectors have been deliberately designed and assigned to physically enforce a safe network topology.

In other contexts, such as plumbing, one-way flow is not enforced through connector gender assignment. Flows through piping networks can be bidirectional, as in underground water distribution networks which have designed-in redundancy. In plumbing situations where one-way flow is desired, it is implemented through other means (e.g. air gaps or one-way check valves), and not through male-female gender schemes.

Early mentions of the metaphor<br>[edit]

Universal Etymological English Dictionary mentioning male and female screws in 1731<br>The Talmud describes arrow heads and mating shafts as potentially being either male or female, depending on their construction, i.e. a prong on a male arrow head fits into a hollowed out shaft and vice versa. This is owing to a prohibition on a female shaft, from its susceptibility as a receptacle for impurity, for use as s'chach.[4]

18th-century dictionaries and encyclopedias mention male and female screws or cochleae.[5] A 1736 builder's manual mentions screw genders as metaphors for convex and concave shapes:

If the furrowed surface be convex, 'tis called a Male Screw; if concave, a Female; and where Motion is to be generated, the Male and Female are always join'd.[6]

Mechanical fasteners<br>[edit]

Female nut threaded onto a male boltMain article: Fastener

In mechanical design, the prototypical male component is a threaded bolt,[7] but an alignment post, a mounting boss, or a sheet metal tab connector can also be considered as male. Correspondingly, a threaded nut, an alignment hole, a mounting recess, or sheet metal slot connector is considered to be female.

While some mechanical designs are one-time custom setups not intended to be repeated, there is an entire fastener industry devoted to manufacturing mass-produced or semi-custom components. To avoid unnecessary confusion, conventional definitions of fastener gender have been defined and agreed upon.

Modular construction toys<br>[edit]

Lego toy brick connections are female underneath, and male on top<br>Several common construction toys embody gendered (and in some cases, genderless) mechanical interconnections. For example, the canonical Lego plastic blocks have female indentations on the lower surface and male bosses, or protrusions, on the upper surfaces. Meccano and Erector have many gendered connections, starting with the nut-and-bolt fasteners they use frequently.

Stickle bricks, using interlocking plastic protrusions, are effectively genderless (while nonetheless maintaining an asymmetry). Lincoln logs use a very simple form of genderless connections. Kapla or KEVA planks are extremely simple genderless systems interconnected only by gravity.

Mathematicians have begun to classify...