The primary difference lies in their application and how they manage mechanical stress.

• Pin Insulators are designed for a lighter, vertical load. Their main purpose is to support the conductor on straight sections of the line, keeping it isolated from the pole. The conductor is tied into a groove on the top of the insulator.

• Shackle Insulators are designed to handle high tension and heavy mechanical stress. They are used at dead-end poles and line corners where the conductor's pull is significant. Shackle insulators absorb this tension and can be oriented horizontally or vertically to suit the line's configuration.