Which description best matches what a cylinder bore gauge reveals about a bore?

Which description best matches what a cylinder bore gauge reveals about a bore?

• A. It shows surface roughness.
• B. It shows diameter only.
• C. It shows out-of-roundness and taper.
• D. It shows straightness.

Answer: (C)

A cylinder bore gauge is used to assess the size and geometric condition of a bore. It doesn't just tell you the diameter; by taking measurements at several depths and around the circumference, you can detect whether the bore stays the same diameter all the way through and around. That reveals out-of-roundness in the cross-section and taper along the length. Surface roughness is a microscopic texture measured with a profilometer, not with a bore gauge. Straightness concerns the bore axis alignment, which isn’t the primary reading from a bore gauge—the instrument is built to reveal diameter variations that indicate roundness and taper. Therefore, the description that best matches what a cylinder bore gauge reveals is out-of-roundness and taper.

A cylinder bore gauge is used to assess the size and geometric condition of a bore. It doesn't just tell you the diameter; by taking measurements at several depths and around the circumference, you can detect whether the bore stays the same diameter all the way through and around. That reveals out-of-roundness in the cross-section and taper along the length. Surface roughness is a microscopic texture measured with a profilometer, not with a bore gauge. Straightness concerns the bore axis alignment, which isn’t the primary reading from a bore gauge—the instrument is built to reveal diameter variations that indicate roundness and taper. Therefore, the description that best matches what a cylinder bore gauge reveals is out-of-roundness and taper.