What happens if we do not reduce friction in machines?

If we do not reduce friction, there are many problems for machines. The parts that are moving will rub together very hard. This will make so much heat. Sometimes, the machine gets too hot and can even stop working. This is very bad.

Also, the parts will get damaged. They will wear out very fast because of the rubbing. You will have to change the parts again and again. This costs more money.

The machine also becomes very slow. It needs more power, like more petrol or more electricity, to do the same job. So much energy is wasted just fighting the friction. So, it is not efficient. For a machine to work smooth and for long time, we must reduce friction.