The electrical outlet and power plug type F are largely used in Eastern Europe, Germany, Sweden, Austria, Norway, Portugal, Finland, and Spain.
In electrical circles, the type F plug is known as the CEE 7/4, but in the various countries it’s used, it has been nicknamed the “Schuko plug.”
“Schuko” was coined from “Schutzkontakt,” a German word that translates “safety contact” or “protection contact.”
The F plug and electrical outlets traces its origin to post-World War I Germany.
A patent (DE 370538), which featured the F plug’s design, was granted to a Bavarian manufacturer of electrical accessories, Albert Büttner, in 1926.
The type F plug bears similarity to the type C plug, but the conductive clips in the top and bottom indentations, which earths the plug, are the major difference between them.
The F plug is not perfectly round but has plastic notches on both sides, which provides stability for large and heavy plugs.
The F plug’s two pins have a 4.8 mm diameter and are 19 mm long, separated by a 19 mm distance.
Also, The distance between the middle of the imaginary line connecting the center of the power pins and the two earthling clip lines is 16 mm.
You can insert the plug into the receptacle in any direction, and because of this, the neutral and line connections are made randomly.
Any appliance that uses the CEE 7/4 plug is usually rated 16 amps and must either be connected to a higher source such as the IEC 60309 system or the mains.
The type F plug is now compatible with type E sockets, after years of incompatibility.
The universal Continental European standard E/F plug was developed to bridge the difference between the two types of plugs, which emanated from grounding issues.
The earthed hybrid E/F plug known as the CEE 7/7 has earthing clips on both sides to ensure the type F socket mates.
There’s also a female contact to accept the type E socket grounding pin. The initial F plug, which was in circulation, has no female pin and is no longer in circulation.
They can be found in various DIY rewireable shops. Type F sockets can accept type C plugs.
Due to the fact that the plug is recessed about 15 mm, plugs that are inserted halfway are not at risk of electrocuting anyone.