Dial Indicators: Most Recommended Models of 2020
Best for repetitive and comparative measurements, the dial indicator is an inspection and measurement device often used to check the variation of a machined part’s tolerance by measuring linear movement. To maintain straightness, the dial is mounted to a fixture which enables vertical movement to ensure that the contact point always lands in the same place, relative to the fixture. Therefore, the dial indicator must be oriented vertically to whatever is being measured.
Despite the common name, dial indicators are anatomically very different from dial test indicators. In this article, we’ll dig deeper into dial indicators, explore their functions, features, and take a look at the most recommended models by our community.
To learn more about the differentiation between the two tools, check out Choosing the Right Dial Indicator. If you’re interested in learning more about dial test indicators, read about the Top 5 Dial Test Indicators of 2020.
Dial indicators have plunger type contacts that are a spring-loaded part. The plunger is raised or lowered by the surface below and the dial indicator reads that movement. From the zero-reference point there are two basic outcomes that apply. When the plunger moves out of the case and the needle moves counterclockwise, this is a negative reading. Alternatively, when the plunger moves inward, toward the case, the needle movers in a clockwise direction which is a positive reading.
The user must simply note whether the needle lies within the tolerance bands. This is what makes the tool so user friendly as no interpretation is needed.
Though these tools are heavy in weight, do not underestimate how fragile they are. Indicators are very susceptible to damage, so avoid excessive force whenever possible.
The dial indicator is a primary measuring tool in precision engine building. In this case, they are commonly used to measure deck clearances and crankshaft thrust and straightness.
You will also see this tool used frequently in quality checks to confirm consistency and accuracy in the production process.
Other common uses of the tool include measuring:
- Value lift
- Journal concentricity
- Flywheel or a brake rotor run out
- Gear backlash
- Crankshaft end play
Make these best practices a habit so your tool performs successful measurements and lasts a long time.
- Ensure that your dial indicator is nuzzled up close to its mount to minimize the risk of rod deflection.
- Keep the reference surface, the test base, and the indicator spindle clean.
- Test the readings multiple times throughout the day to ensure accuracy. This can be done by comparing the reading to a master part.
Keep your indicator safe – they are a highly delicate tool! If you drop or damage your dial indicator, it is important that you test it thoroughly before allowing it back into production.
To help you identify which dial indicator is best for you, we reached out to the Practical Machinist community via social media and gathered a list of their favorite models. Here are the top 5 dial indicators models they recommended.
Used to measure dimensional deviations with graduations of 0.0005” and accuracy up to +/- 0.0005”, this dial indicator features a light green face to provide comfort on the eyes. This tool features jeweled bearings that resist friction, hobbed gears to promote more sensitive responses, and weighs about 3 pounds.
The Mitutoyo dial indicator comes with the choice of a flat or lug back, so it is compatible with a variety of mounting options. You can also choose between a black or white face depending on your preference.
The 2-1/4” diameter rotating dial indicator makes this too great for both vertical and horizontal measurements. The dial indicator reads to 0.001” and features a bright orange hand to make readings as easy as possible.
The Fowler dial indicator features a lug back, so make sure you have a compatible mount (or purchase one accordingly). The spindle and contact points are stainless steel to support longevity. Nothing but good words surround this tool.
Despite the low-price tag on this tool, the Practical Machinist community confirmed that reliability is definitely not sacrificed. This dial indicator has even been compared to the Mitutoyo model due to its accuracy and sturdiness.
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