The twist and lock style bayonet light bulb mount was first developed in the UK in the 1860s. It remains the standard bulb fitting in many former members of the British Empire including Australia, India, Ireland, New Zealand, and Hong Kong, among others (largely excluding the United States, Canada, and Mexico which primarily use Edison screw sockets)
Bayonet-style bulbs were often found with two or three pins to ensure a solid connection with the mounting socket.
The Bulb’s nomenclature can be deciphered as follows:
BA – Bayonet
15 – Diameter of the bulb cylinder in mm
D – either S for ‘single’ or D for ‘dual’ contact point at the base
How they’re used:
Bayonet-style bulbs are incredibly useful for their ability to maintain a solid connection in environments that would be susceptible to vibration. You will often find the BA15D in automotive or maritime applications for this reason. Another example where the BA15D can be found would be in elevator lighting. However, they are found in other stationary locations as well such as landscape or interior lighting because of their ease of installation.
Why you want them:
With modern LED technology, the BA15D has been improved significantly from where it began. EmeryAllen is pleased to offer these high-performance, long-life bulbs with our trademark color rendition, and lifetime warranty.
If you have any questions about our BA15D light bulbs or our other products, feel free to contact us.