What tool is commonly used to ensure correct clearance in ball bearings?

The tool commonly used to ensure correct clearance in ball bearings is a plastic gauge. This gauge is specifically designed to measure the clearance between the bearing and its housing or the shaft. It consists of a soft, malleable material that is placed between the two surfaces. When the bearing is installed and torqued to specifications, the plastic gauge gets compressed, allowing an accurate reading of the clearance by observing the thickness of the gauge that has been flattened.

Using a plastic gauge is beneficial because it provides a direct measurement that reflects real-world conditions when the bearing is installed, unlike some other measuring tools that may not account for the actual compression and fitting of the bearing components. This makes it an essential tool for millwrights when setting up precise machinery with ball bearings to ensure optimal performance and longevity.

Other options, while they have their uses, do not provide the specific functionality needed for measuring the correct clearance in ball bearings. For instance, feeler gauges are typically used to measure gaps but may not offer the same level of accuracy in this particular application. A calibrated ruler could provide basic measurements, but it lacks the precision necessary for bearing clearance. Laser alignment tools are used for aligning shafts and machinery components instead of measuring clearance.