Micrometers are computers used by engineers to measure thickness and internal and external depths accurately. Unlike other gauges such as vernier and caliper, its results are safe and are easy to use. This invention is based on the micrometer screw, a device developed in the 17TH century, but in principle was used to measure distances. The mechanism consists of two-headed away or closer by a screw thread. Then it it is adapted for small precision measurements, since you can do it with hundredths of millimeter. He began to be marketed en masse during the industrial revolution. Micrometers are very appreciated by the accuracy of their measurements.

They are based on the principle that says that if a screw is rotated about a nut displacement lengthwise or longitudinal, is equal to the given turn. This device is composed by: body or frame. The stem, which is a movable element that helps the reading of measures. The stop, which determines the zero from which the measurement is made. The clamping nut, which serves to lock the PIN. The ratchet or clutch, which compensates the force exerted to make measurement.

Fixed drum, where the scale that goes from zero to twenty-five is recorded. Mobile drum, which has recorded the sliding scale with fifty divisions. The market offers us different micrometers which vary in the scale used. There are three types of micrometer depending on what to measure: depth micrometer: measured differences in length between two parallel measures. Internal micrometer: measured interior parts of the piece, so that it is based on three points of support, as hollow with an opening. External micrometer: measures the outside of parts, e.g. used for areas blocks, wire. The possibilities of technological advances have also allowed greater precision devices that allow us to differentiate between two types: micrometer manual or mechanical. The electronic micrometer, which uses digital technology, some can do it with up to one thousandth of precision. The sale of micrometers has remained constant in recent years by the variety of possibilities that give these instruments of measurement, since it is the most used tool in mechanical industries who appreciate a precise tool that helps them to minimize risks and reduce losses.