2-20 Pin: This pin acts as a connecting or locking component within the hammer drill’s mechanism. It helps secure parts of the hammering system and ensures the components stay in alignment and function correctly under impact and vibration.

Spring: The spring provides tension and helps control the movement of the hammering mechanism. When you engage the hammer mode, the spring compresses and releases in sync with the drill’s action, creating a reciprocating motion that delivers the hammering force needed to break through hard materials like concrete or masonry.