Micrometers are vital for measuring small objects, verifying parts to specifications, and checking measurements to be within tolerances. But even the most experienced person can make mistakes when using this tool. Avoid making these common mistakes if you want the most accurate measurements possible.
1. Applying Too Much or Not Enough Pressure
Micrometers should have steady, even pressure when taking measurements. Too little pressure, and you'll get a false reading. Too much pressure, and you risk deforming your tool. It should be tight enough to keep a gage block from slipping and loose enough to move easily between the faces. Aim for a snug feel. When done correctly, you should be able to measure less than plus or minus .0001" every time.
2. Misreading the Micrometer Scale
With analog micrometers, read the whole scale, not just the largest divisions. Remember, the micrometer has two scales: the main scale on the barrel and the second scale on the thimble. Take the measurement where the anvil and spindle meet at the object's center.
Also, be mindful of your micrometer units. Manufacturers use the imperial or metric system, depending on where they're sold. For example, on the sleeve scale, the metric has 50 divisions while the imperial has 40. If your micrometer doesn't include both systems, you'll need to convert between the two in your measurements.
3. Not Calibrating Regularly
We often use micrometers for inspection. Thus, their measurements must be accurate and reliable. Regular calibration helps ensure the micrometer's accuracy and repeatability. If not, you risk damaging your equipment and inaccurate measurements. The calibration interval depends on usage, measuring accuracy, quality assurance requirements, and environmental factors. Ensure the accuracy exceeds a 4:1 ratio over the calibrated gauge's accuracy. Gage blocks have a specific tolerance and accuracy greater than the micrometer's accuracy.
4. Not Taking Multiple Readings
When measuring with a micrometer, take multiple readings to get a precise measurement. Depending on the precision level, you may need to take several readings and average them. An average is a better indicator of the actual value than one measurement. Multiple readings allow you to check the consistency of your results. The more measurements you take, the more precise your measurement will be.
5. Not Zeroing Out the Instrument
The biggest mistake people make is not zeroing out a micrometer before use. Zeroing out a micrometer is easy to do and only takes a few seconds. The micrometer has a screw that you can use to adjust the anvil to level with the spindle. When they're both closed together, the scales will read zero. Once you've done this, your micrometer is ready to take accurate measurements.
6. Not Choosing the Right Micrometer
There are many different micrometers, each designed for specific purposes and applications. Choosing the right one depends on what you're measuring, the accuracy your work requires, and environmental factors.
The most common type is the outside micrometer, which measures an object's external dimensions. An inside micrometer is best for measuring the inside dimensions of holes and registers. Depth micrometers measure the depth of a hole and bores. You'll get inaccurate results if you're the wrong micrometer. Make sure you're using the proper tool for the job.
7. Not Holding the Micrometer Correctly
Ask a dozen people how to hold a micrometer, and you'll get a dozen answers. We suggest holding the micrometer level and perpendicular to the surface you're measuring. Hold the thimble in your dominant hand between your thumb and index fingers. The C-shape frame should rest against your palm; this is where most of the weight will be. Then use another finger to hold the inside of the frame. Use your non-dominant hand to hold the object you want to measure. The measured object should be flush with the anvil to get an accurate reading.
Although micrometers are accurate tools, they are prone to errors when not used right. If you take proper precautions, you'll be able to take measurements you can count on every time. Are you in need of a micrometer? We offer a wide selection of micrometers from industry-leading brands. Find the best one for your needs today.