Things You'll Need:
- Calipers
- Micrometers
- Indicators
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Step 1
Use a dial caliper to measure the outer diameter of machine parts. Open the caliper with the thumb wheel on the left side, and lightly close the blades on each side of the area to be measured. This will give you the outer dimensions. Look at the slide on the left blade, this will give you the first part of the dimension, then add the amount on the dial to get the total dimension. If the blade is past the large 2, slightly past the smaller 5 and the dial is pointing to 10, the dimension is 2.51".
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Step 2
Find an inner diameter measurement with a digital caliper. Insert the small blades on the top of the caliper into an inner diameter, and slowly move the thumb wheel to the right to expand the blades. When they hit each far side the measurement window will tell you the dimension, either in millimeters or inches.
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Step 3
Use a micrometer to measure outer diameters of small parts. These measuring instruments are very accurate and come in many sizes. Most sets have micrometers to measure from 1 inch all the way up to 3 inches. Place the object between the anvil and the spindle, and twist the thimble until the spindle touches the other side of the diameter you are measuring. The dimension on the sleeve is added to the dimension noted on the thimble to get your outer diameter size.
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Step 4
Use a depth micrometer to measure the depth of flat-bottom holes and slots. Place the reference plane on the top surface, and twist the spindle until the bottom of the measuring rod touches the bottom surface to be measured. Read the dimensions like that of an outer diameter micrometer; add the sleeve dimension to the spindle dimension to get your reading.
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Step 5
Use a dial indicator to measure small precision parts. Set the indicator on a flat surface and lower to just above the part to be measured. Push the indicator's point onto the highest area of the part, and re-zero the indicator by turning the bezel and setting this point as your new zero. Move the part back and forth to make sure that the highest point is indicated at that new zero. Take any new parts and slide them under the indicator to make sure that they are of the same size.
