Which tool would you use to check straightness of an arbor?

Which tool would you use to check straightness of an arbor?

• A. An Indicator
• B. A Micrometer
• C. A Caliper
• D. A Dial Test Indicator

Answer: (A)

To check straightness, you need a device that senses tiny linear deflections and shows them clearly. An indicator does exactly that: a dial or digital readout translates a small tilt or bow in the arbor into a readable value. By mounting the indicator and moving it along the length of the arbor (or rotating the arbor and comparing readings along its length), any deviation from a straight line becomes evident on the indicator. Micrometers and calipers measure size, not shape along the length, so they aren’t suited for assessing straightness. A Dial Test Indicator is a specific type of indicator typically used for runout and alignment, but the essential tool for detecting straightness is the general indicator, which provides the sensitive, direct readout of deviations you need.

To check straightness, you need a device that senses tiny linear deflections and shows them clearly. An indicator does exactly that: a dial or digital readout translates a small tilt or bow in the arbor into a readable value. By mounting the indicator and moving it along the length of the arbor (or rotating the arbor and comparing readings along its length), any deviation from a straight line becomes evident on the indicator.

Micrometers and calipers measure size, not shape along the length, so they aren’t suited for assessing straightness. A Dial Test Indicator is a specific type of indicator typically used for runout and alignment, but the essential tool for detecting straightness is the general indicator, which provides the sensitive, direct readout of deviations you need.