Elevator Mechanic Practice Exam

You are on a call and find the pulley came off the pump motor and the set screw is missing, what kind of screw would you use to replace the set screw?

1. Allen Screw

2. Cap Screw

3. Cup Screw

4. Hex Screw

The correct answer is: Cup Screw

The most appropriate choice for replacing the set screw in this scenario is often associated with the specific design and function of a set screw. A set screw is typically used to secure one object within another, often without a visible head, making it less likely to get caught or damaged during operation. A cup screw, which features a rounded or cupped head and is designed to be used within a variety of mechanical applications, can indeed provide the necessary grip required for maintaining the position of the pulley on the pump motor shaft. This design can ensure it remains seated correctly, reducing the likelihood of slippage. In contrast, while Allen screws, cap screws, and hex screws provide unique features, they may not serve the specific functional requirement as effectively as a cup screw in this context. Allen screws require an internal hex to drive, which might not be practical for a quick repair. Cap screws have a full head dominant in many applications, and hex screws would also have a fully visible standard head, which could cause potential interference in tight spaces or mechanical assemblies where minimal projection is needed. Therefore, selecting a cup screw fits the requirement for securing components while minimizing risks associated with protrusions.