A Fahnestock clip is an early type of spring clamp
electrical terminal for connections to bare wires. It is still used in educational electronic kits and teaching laboratories in schools. It is designed to grip a bare wire securely, yet release it with the push of a tab. The clip was patented in the United States on by John Schade Jr., assigned to Fahnestock Electric Co. Less than two weeks after the patent was issued they filed for reissue.
It consists of a single flat piece of springy metal, bent over itself to form a clip. Pushing down on the end of the metal tab opens a hole through which a bare or
stripped wire
A wire stripper is a small, hand-held device used to strip the electrical insulation from electric wires.
Types
Manual
A US-style simple manual wire stripper is a pair of opposing blades much like scissors or wire cutters. The addition of ...
can be inserted. Releasing pressure allows the tab to spring back, closing the hole and gripping the wire to form an electrically sound mechanical connection. Pushing the tab again releases the grip on the wire so it can be withdrawn.
Modern
banana plugs will usually fit into a Fahnestock clip, although the fit is tight.
Fahnestock clips were commonly made of
phosphor bronze or
spring steel and plated with
tin or copper for good
electrical conductivity
Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allow ...
and
corrosion-resistance. Most Fahnestock clips seen today are
nickel-plated.

Fahnestock clips were seen on early radio receiver
breadboard
A breadboard, solderless breadboard, or protoboard is a construction base used to build semi-permanent prototypes of electronic circuits. Unlike a perfboard or stripboard, breadboards do not require soldering or destruction of tracks and are ...
construction,
model train
Railway modelling (UK, Australia, New Zealand, and Ireland) or model railroading (US and Canada) is a hobby in which rail transport systems are modelled at a reduced scale.
The scale models include locomotives, rolling stock, streetcars, t ...
power connections, and the like. They were also available on early dry batteries. Today, they have largely been supplanted by
binding posts. However, they remain in use in elementary schools especially, where their ease of use and visible connections make them a popular way for science instructors to teach the creation of simple circuits, and most university
physics departments still have them on apparatus.
Fahnestock clips are also used as safety devices on the arming wires of aircraft bombs; their grip on smooth bare steel wire is sufficient to prevent the wire from being withdrawn from a fuze during normal handling but light enough to allow the wire to be withdrawn when the weapon is released.
References
{{Reflist
Electrical signal connectors
DC power connectors