Several socket outlets made by MK.
Oval MK logo at the centre of the plate.
Moulded On and OFF legend abouve and below the switch. Two fixing holes. These are the same spacing as modern socket outlets.
The back is made from moulded brown plastic, with terminal markings and other information moulded into the plastic. The terminal holes have a high quality clamp type mechanism, where the wires are clamped between two flat pieces of metal, rather than the screw contacting the wires directly.
Oval MK logo on the front between the socket holes.
Part numbers are 5247 for the socket mechanism and 5248 for the socket front plate. Other markings on the back include 13A 250V, AC ONLY, PATENT and MADE IN ENGLAND.
The terminals themselves are very substantial and far larger than those on modern socket outlets.
Note the fixing holes are on the top and bottom edges, rather than the sides. Modern boxes still have fixings in these positions, so this could be used on a modern box.
This example is extremely worn, the entire face is scratched and covered in thick layers of emulsion paint.
Rear terminals are again substantial compared to modern equivalents.
Plate part number 5286, socket part 5285. Other markings include 13 AMP, 250V, TO BS 1363, MADE IN ENGLAND.
The oval MK logo appears on the front of the plate and the back of the socket mechanism.
Single oval MK logo at the centre of the plate.
The outlets are not vertically centred on the plate - they are positioned towards the top, leaving a much larger space under the live/neutral holes. This would have allowed this outlet to be fixed very close to the floor, as there is more space for the flex to bend underneath the plug.
Two fixing holes, same spacing as modern sockets. The outlets are vertically centred on the plate.
This example has signs of overheating on the left outlet - the hole for the live plug pin is discoloured. This was probably due to a plug with a loose connection, causing the plug pin to heat up when in use.
DIY decorators have also been at this, which is why there is emulsion paint all over it.
Unlike the other examples, this has four fixing holes, two on each of the longer edges. Boxes of the same age as this outlet typically had 6 fixings - two on each longer edge, and one on each shorter edge. Modern sockets with two fixing holes will therefore fit onto old boxes, but old sockets like will not fit onto new boxes, as they only have the two side fixings.
This example was removed from a kitchen, which is why the switches are caked in ancient grease.