Museum of Plugs and Sockets logo, small BS 372 : 1930 Part I
not earthed plugs and sockets
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BS 372:1930 Part I was the last BS 372 standard for not earthed, 2-pin plugs and sockets. Images 1-14 show examples that date back to the 1930s - '60s. The use of not earthed sockets and plugs ended in 1970 when BS 373 Part I was withdrawn, following the introduction of BS 4573.

BS 4573:1970 defines 2-pin shaver plugs and special shaver sockets, shown in images 16-18. They are the only not earthed domestic devices that are allowed nowadays in the UK. A concise history of British not earthed plugs is given a separate page

 

BS 372 Part 1, 5A socket
BS 372 Part 1, GEC 5A plug
Clix 2-pin 10A plug
BS 372 Part 1, Clix 15A plug

Clix 2-pin plug with grub screw for cord fixation
Clix system for wire attachment to plug pins
BS372-like 5A 2pin plugs


Specification of pin diameter, length and spacing are given in a table below.

1 BS 372 Part I, Bakelite, surface mount 2-pin 5A socket. Indicated is U.K. Patent No. 473440 for "Improvement in and relating to sockets and socket mountings for electrical plug connections", granted to Ward & Goldstone in 1937.   {JM}
2 BS 372 Part I plug, rated at 5A - 250V. Such flat top models existed for 2A, 5A and 15A and were made in England by General Electrical Company in the 1930s to (at least) 1950s. The Standard refers to "Two-pin Side-entry Wall Plugs and Sockets for Domestic Purposes", as the GEC plug shows.   {DP}
3 Two pin 10A plug made by Clix*. A rating of 10 A is an uncommon 'relict' of the old Union gauge (see historic note below). It did not comply to BS 73 and following BS 372. These standards described 2A, 5A, 15A and 30A only. Plug dating: possibly 1950s.
* Clix plugs had an unique type of wire attachment; image no. 6 shows the principle in detail.
4 CLIX BS 372 Part I plug, rated at 15A - 250V. The plug has a cord side entry, comparable to plug no. 5. Image nos 1 to 4 are shown in proportion to each other.   {GP}
5 5A CLIX type 5/2/B plug. Flex cord is gripped by a grub screw (made of wood), an improvement that has been patented by Charles Reginald Cook (Chesworth, Horsham, Sussex). Patent no. GB426943, granted on December 28, 1933. The patented CLIX wire fixation system is show in detail in image no. 6.   {MS}
6 CLIX type 5A plug, which allows the attachments of wires without using any tools.
The principle of wiring a CLIX plug: [1] unscrew cap; [2] release pins by pressing them inwards; [3] put wire through the loop of a pin; [4] insert pin with wire into the base of the plug and press the pin fully down; [5] screw the cap tightly down (this is essential to keep the wires in a safely locked position !).
The wire fixation system has been patented by four patents (GB371404, GB371418, GB403448, GB457113), granted between April 18, 1932 and October 4, 1935 to C.R. Cook.   {RM}

Note that the flex cable entry is opposite the plug face. Although top entry plugs were very common in the UK, they do not fully comply with BS 372 Part I or the preceding BS 73. British Standard require that the cord enters at the side (note given by David Peacock).
7 Two 2-pin plugs. The plug left shows the text: 5A.250V. B.S.GAUGE and has been made by General Electric Company. Pin spacing (16.7 mm) and diameter of pins (5.1 mm) are in accordance with BS 372 Part I, but pins are shorter: 13.3-13.5 mm, rather than 15.9 mm.   {Asw}
The 5A 2-pin plug right was generally used for flex cords (note given by Terry Weids). Plug does not have any indication of the manufacturer, other than "Made in England". Dating: 1960s.


MK Electric BS 372 Part 1 5A socket with switch BS372 5A 2 pin Coltone multiplug BS372 5A 2pin Goltone multiplug top BS372 5A 2pin multiplug

Grelco BS 372 Part 1, 2-pin dual plug with outlets for 5A and 2A Grelco BS 372 Part 1, 2-pin dual plug with outlets for 5A and 2A
BS1363 multi-purpose plug

8 Surface mount 5A BS 372 Part 1 socket with switch. Manufacturer: MK Electric. Dating: late 1960s.   {DH}
9, 10
Bakelite 2-pin multi-plugs. An appealing, classic design made by Ward & Goldstone, who used the trademark Goltone. The inscription on top warns that the maximum load may not exceed 5A, 250V.   {ASw}
11 White plastic 3-way 5A, 2-pin multi-plug. Brand name: Clang.   {ASw}
12, 13
BS 372 Part I, 5A multi-plug with outlets for 5A and 2A BS 372 Part I plugs. Made in England by Grelco.   {DP}
14 3A BS 1363 multi-plug, 'Empire Made' by Livia Electrical (model 5067). Besides a single BS 1363 outlet (with shutters) it also has two outlets for 5A 2-pin plugs. In the 1970s and '80s it was quite common to have 2-pin plugs on small appliances. The 2-pin outlets were convenient when people moved house or had their house rewired, but didn't like to change the plug of some lamps etc.   {DF}

Obsolete Britsh polarized 2-pin connector plug
GEC 1934 catalog, page 56

15 Polarized 2-pin connector plug, MADE IN ENGLAND. Rating: 10A - 250V. General Electric Company shows in the 1934 catalog - section 'Polarity Patterns' - a similar socket and plug (image right). It seems that there was a manufacturer logo below the horizontal slot, but it is not clear whether it was the GEC logo. The connector does not comply with BS 372.

Neither US T-slot (NEMA 2-20) nor Australian Extra Low Voltage plugs fit in the British connector, because of differences in flat pin size and spacing.



 BS 4573 shaver socket and plug


BS 4573 shaver plug
BS 4573 dual voltage shaver socket
BS 1363 shaver adaptor

Safety.  Electric shavers have to be supplied with a shaver cord that has a 2-pin plug. It prevents that shavers are directly plugged into a BS 1363 socket. The use of these sockets in wet rooms may cause electrocution. A 2-pin shaver socket is safe and legal alternative.
Also in many hotels, worldwide, shaver socket are installed in bathrooms.

16 BS 4573 two-pin reversible plug, moulded to a curly shaver cord. Pin diameter (5.1 mm) and spacing (16.7 mm) is identical to BS 372 Part I 5 Amp plugs. The other end of the shaver cord has a 0.2A IEC 60320-C1 appliance connector. BS 4573 plugs have a top end cord entry, rather than side entry which is compulsory for all BS 372, BS 546 and BS 1363 plugs.
Manufacturer of shaver cord: LEONI, German company that produces a large range of wire products.    {DF}

BS 4573 plugs resemble Europlugs (CEE 7/16), but British plugs does not fit in continental European sockets, because of differences in pin diameter and pin spacing.
Europlugs have 4.0 mm pins and a pin spacing that tapers from 18.6 mm (plug base) to 17.5 mm (pin tip); see inset. These non-parallel and to some degree flexible pins ensure sufficient contact when a Europlug is inserted in a CEE 7/3 (Schuko) socket with 4.8 mm contacts.
17 BS 4573 dual voltage shaver socket with shuttered outlets, rated at 200 mA. Socket has an isolating transformer that complies to BS 3535. The shaver symbol is compulsory.
Round pin contacts have an elongated shape that allows the use of both shaver cords with BS 4573 and Europlugs.
18 BS 1363-3* adapter for a BS 4573 shaver plug. It is an older model; from 1994 partially insulated L and N pins are compulsory.

* Part 3 of the BS 1363 standard gives specifications for adapters. Shaver adapters must have a 1A fuse, safety shutters, power pins with insulating sleeves and a FOR SHAVERS ONLY indication.
Instead of a brass earth pin, a shaver adapter may have a plastic Insulated Shutter Opening Device (ISOD).   {DF}

 

Characteristics of BS 372 Part I plugs
current rating
pin diameter
pin length
pin spacing
(centre to centre)

2A
3.6 mm
12.7 mm
12.0 mm
not in collection
  5A  5.1 mm
15.9 mm
16.7 mm

10A
5.0 mm 19.6 mm 19.5 mm
15A
7.0 mm 20.6 mm 22.3 mm
30A
7.9 mm
28.6 mm
32.0 mm
not in collection
Specifications of BS 372 Part I plugs differ from line and neutral pins of 3-pin BS 372 Part II plugs.
Consequently, not earthed plugs don't fit in earthed sockets that have the same current rating.

The South Africa classic page shows an example of an old, wooden 2-pin plug and socket.

 


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