“Papa, when we change a light bulb, we do not replace the holder. Similarly, when we buy a two-pin plug, we do not change its holder either. Many companies manufacture plugs and other electrical fixtures, but we never look for these things at any shop,” said Raju.
“Yes, Raju. General items are made to general standards. But each manufacturer may have an exclusive set of items manufactured only by them and the parts that only fit with their products. For example, a headlight assembly of a car from one make may not fit into a car of another make – but the bulb will fit. Similarly, the fixtures holding a tube light may vary but the tubes are of fixed dimensions. These items are called ‘consumables’; which means they may need to be replaced. Their life is less as compared to the fixtures into which they are fitted,” his father explained.
“You will find that almost every item that we buy is made to some fixed standard specifications. And there will be several manufacturers of these items. Take the example of the bulbs as you pointed, there are different types of bulbs, such as LED, incandescent, CFL, etc, but the method of holding the bulb is either a plug-in-and-turn or a threaded-type. There are a number of different brands manufacturing both the holders and the bulbs, but one make of bulb or the tube light fits into another make of the holding fixture. These standards are now followed worldwide to make things simpler and the seller does not have to keep stocks of different brands with different types of fitments. This will be true for certain items. But some manufacturers will have their own designs as I mentioned earlier about the headlights of a particular car. In this case, we buy replacement items manufactured by the OEM (Original Equipment Manufacturer) suppliers,” he continued.
Demonstrating further, he added, “For example, if x manufactures an item for a car company, then the same part is also made available as a spare in the market as a genuine spare which is used in the original assembly by the car manufacturer. There will be lookalikes or what we call duplicate ones which will be cheaper versions of the original and are dimensionally the same as the original ones. There is a huge market for such products as the originals are sometimes very costly owing to the quality or limited supply.”
“Papa, is this the reason that there are service centres of various brands that they do not accept other brands for servicing?” asked Raju
“Yes Raju, each manufacturer – be it a car manufacturer or a TV manufacturer or a smartphone manufacturer – has a list of parts for every model it makes as per the design of the model. When we a part needs to be changed, they will replace it with the correct part as per the list and if they don’t have one they will order it from the company or the OEM supplying to the company.”
(Writer is a mechanical engineer and runs a hands-on science activity centre at Margao.)