Editing Electrical connector (section)

===Materials===
Electrical connectors essentially consist of two classes of materials: conductors and insulators. Properties important to conductor materials are contact resistance, [[Electrical conductivity|conductivity]], [[mechanical strength]], [[formability]], and [[resilience (materials science)|resilience]].<ref name="molex">{{cite web |url=http://www.piclist.com/images/com/marvin3m/www/http/connect/index.htm |title=Molex Connectors Explained, as used in Pinball |date=4 March 2005 |website=Marvin's Marvelous Mechanical Museum |access-date=1 July 2019}}</ref> Insulators must have a high [[electrical resistance]], withstand high temperatures, and be easy to manufacture for a precise fit

[[Electrode]]s in connectors are usually made of [[copper alloy]]s, due to their good conductivity and [[malleability]].<ref name="zvei" />{{rp|15}} Alternatives include [[brass]], [[phosphor bronze]], and [[beryllium copper]]. The base electrode metal is often coated with another inert metal such as [[gold]], [[nickel]], or [[tin]].<ref name="molex" /> The use of a coating material with good conductivity, mechanical robustness and corrosion resistance helps to reduce the influence of passivating oxide layers and surface adsorbates, which limit metal-to-metal contact patches and contribute to contact resistance. For example, copper alloys have favorable mechanical properties for electrodes, but are hard to solder and prone to corrosion. Thus, copper pins are usually coated with gold to alleviate these pitfalls, especially for analog signals and high-reliability applications.<ref name="gold-tin">{{cite web |url=https://www.connector.com/gold-or-tin-versus-gold-and-tin/#ixzz4irNbDrRT3 |title=Gold or Tin versus Gold and Tin? |website=Molex |last1=Endres |first1=Herbert |date=19 December 2011 |access-date=1 July 2019}}</ref><ref name="golden-rules">{{cite web |author=AMP Incorporated |title=Golden Rules: Guidelines For The Use Of Gold On Connector Contacts |date=29 July 1996 |publisher=Tyco Electronic Corporation |url=https://www.te.com/documentation/whitepapers/pdf/aurulrep.pdf |archive-url=https://web.archive.org/web/20180329092427/https://www.te.com/documentation/whitepapers/pdf/aurulrep.pdf |archive-date=29 March 2018 |url-status=dead |access-date=1 July 2019 |quote=Gold is generally specified as a contact coating for low level signal voltage and current applications, and where high reliability is a major consideration}}</ref>

Contact ''carriers'' that hold the parts of a connector together are usually made of plastic, due to its insulating properties. ''Housings'' or ''[[#backshells|backshells]]'' can be made of molded plastic and metal.<ref name="zvei" />{{rp|15}} Connector bodies for high-temperature use, such as [[thermocouple]]s or associated with large [[incandescent lamp]]s, may be made of fired ceramic material.