1. Always stop the work before you take a measurement. DO NOT measure moving parts because the micrometer may get caught in the rotating work and be severely damaged.
2. Always open a micrometer by holding the frame with one hand and turning the knurled sleeve with the other hand. Never open a micrometer by twirling the frame, because such practice will put unnecessary strain on the instrument and cause excessive wear of the threads.
3. Apply only moderate force to the knurled thimble when you take a measurement. Always use the friction slip ratchet if there is one on the instrument. Too much pressure on the knurled sleeve will not only result in an inaccurate reading, but also will cause the frame to spring and force the measuring surface out of line.
4. When a micrometer is not in use, place it where it will not drop. Dropping a micrometer will cause the micrometer frame to spring. If you drop a micrometer, check it for accuracy before you take further readings.
5. Before you store a micrometer, back the spindle away from the anvil, wipe all exterior surfaces with a clean, soft cloth, and coat the surfaces with a light oil. Do not reset the measuring surfaces to close contact because the protecting film of oil on these surfaces will be squeezed out.