Lightbulb socket

Many of the later standards conform to a general coding system in which a socket type is designated by a letter or abbreviation followed by a number.

[2] The most common type of sockets for mains electricity are Edison screws, used in continental Europe and North America, while bayonet mounts dominate in the Commonwealth countries, except Canada, and in the automotive industry.

Early experimental incandescent lamps employed wire leads which had to be connected to screw terminals, but this was inconvenient for commercial use.

The Edison organization[clarification needed] used simple wooden receptacles with internal copper strips for lamps on the commercial steamship SS Columbia, the first ship to use electric light bulbs.

The contact surface area, thickness and conductivity of the metal, connection methods and maximum operating temperature must all be considered in the design of a new socket.

In addition, mechanical factors such as shape of the socket, fixture mounting and attachment, lamp support, ease of re-lamping and total cost of manufacture must be considered.

Fixtures in such environments may require gaskets or other waterproofing methods to prevent buildup of moisture in the socket area.

One variation is the polarized two-pin socket – used primarily in projectors, which defines the exact positioning of the filament on one side.

The MR16 is an example of this design; the actual lamp is inserted into the reflector with the leads sticking out and a ceramic paste used to glue it in.

Wedge base lamps are widely used in automotive applications, and many Christmas lights strings use plastic wedge-based bulbs.

has been to design newer bases to reduce waste of raw materials and simplify the replacement process.