There are a couple essentials that should be in any tool set for mechanics. One of which are magnetic dial indicators.

Indicators For Magnetic Dials

Magnetic dial indicators are essential for measuring when it comes to building engines. Typically they are used to measure lifter travel, deck clearance, crankshaft straightness, and any additional measurements between two small components or surfaces. Usually a dial with start in increments of .001 inch. Additionally, a magnetic holder for dial indicators can help garner steady accurate measurements.


Indicators for magnetic dials require a secure mounting to function properly, as mentioned above. If any movement occurs while the measurement is being taken the reading will be inaccurate. This is why magnetic base holders are of the utmost importance. This base can be adjusted as needed so that the stem can accurately read in the direction of the part being measured. In some positions this reading can be performed in either direction.


Make sure that the indicator is parallel to the components motion, and then adjust until the stem is around midway between the range of travel between the part you’re trying to measure. Be sure to zero out the indicator before you make any of these adjustments. You can do this by manually moving the dial to the zero mark. Once the magnetic dial indicator is zeroed you can take the measurement by moving the component itself. The measurements you take should fall within .050 of an inch.

Taking Care Of Indicators For Magnetic Dials

Many machinists make the mistake of simply tossing these dials into a tool box and forgetting about them until they need them again. Due to the precision nature of these dials, care must be taken with their handling to ensure they become don’t damaged and ruin results. Keeping them clean, and storing them separately in a place where they won’t get knocked around, is the best way to prolong their usefulness, and keep them in good condition.


Dial indicators are important tools for those measuring small components. If used correctly they can be essential for measuring even the smallest points. However, if not properly held in place by a secure mounting, results will be inaccurate, even from slight movement. Always make sure your indicator is mounted correctly to ensure you always get the correct measurements.