Pin Insulator:- Pin insulators are commonly used on rural and urban primary distribution lines. These can be used up to 33 kV. Pin insulators can be of a single piece or multipiece. The pin type of insulators is uneconomical beyond 33 kV operating voltage. Also, the replacement of these insulators is expensive. For these reasons for insulating overhead lines against higher voltages, suspension insulators are used.
Strain Insulator:- The strain insulators are exactly identical in shape with the suspension insulators. These are used to take the tension of the conductors at line terminals, at angle towers, at road crossings, and at the junction of overhead lines with cables. These insulators are, therefore, known as tension or strain insulators. For low voltage lines (less than 11 kV), shackle insulators are used as strain insulators.