External micrometer

Micrometers for external measurement

The outside micrometer is a measuring instrument designed to measure outside diameters, thicknesses of round mechanical parts or any polygon extremely precisely. The design and main feature of these micrometers for exteriors consists in its particular fork or "U" shape, in which a fixed probe is mounted at one end and a mobile probe at the other end, which performs a displacement along its axis, through a screw-nut system with extremely precise coupling threads made of high-quality steel, hardened and ground. In addition, in order to have the same measuring pressure, they are equipped with a friction system to allow pressure with constant load and to avoid probable measuring errors due to different user sensitivity. At the ends of the fixed and moving probes, carbide pads are fitted.
This application allows the micrometer to measure even metal workpieces of considerable hardness. In fact, hard metal does not wear quickly and is able to maintain the geometry and perfection of the probe planes for a very long time. Its fork and 'U' shape, however, prevents the outdoor micrometers from being flexible in the measuring range. Calibration and adjustment of the instrument's '0' point is done by means of a gauge that is perfectly matched to the measuring range of each outdoor micrometer. The accuracy and resolution of the instrument is usually 0.01 mm hundredths or 0.001 mm thousandths, and they are manufactured in analogue and mechanical as well as digital versions.

Micrometers for external threads: They differ in the shape of the fixed and movable probe, which is made with triangular incisions that allow the thread micrometer probes to wrap around the thread profile and thus measure the average diameter of the external thread. These particular probes are commonly referred to as thread nipples.

External micrometers with lever-type dial gauges: They differ in the fixed probe, which in this case is mobile and connected to a dial gauge. The mobile probe of the external dial indicator micrometer is moved by a lever. It is mainly used when a large number of workpieces have to be selected due to machining errors. By friction-locking the movable threaded probe by means of the lever and the dial gauge, very fast and extremely accurate readings can be taken, drastically reducing the time for 100% production control.

External micrometers with saucers: They differ in that their probes are shaped like saucers and allow chordal measurements to be taken. Chordal measurements are performed when measuring toothed wheels or gears with straight or helical teeth. In the description of the disc micrometer, you will find the modules of the toothed wheels or gears that can be measured.

Micrometers for external measurement with reduced contact surfaces: It differs in the reduced size of the fixed and moving touch probe. Having a reduced probe or plate diameter, this micrometer for exteriors with reduced contact surfaces is excellent for measuring the outside and bottom diameters of splined shafts made to UNI 220 and UNI 221 standards.