Metrology is responsible for the analysis of quantities associated with some type of technological activity, which in practice translates into the determination of the best techniques and equipment for the design and quality control design of a product. As is evident from the field of action that is very broad, and the tools that can be used in the manufacture of mechanical parts is generally spoken of the following elements: .- palmer micrometer or screw consists of a measuring area as C or U, at one end has a screw properly calibrated, which can be moved towards the contact with the element to be measured, as well as a few micrometers have a second screw that allows the tuning of the measure in the handle of this team can identify a level which is covered by the screw further and also evident in this scale, which turns putting the decimal measure, this equipment is highly accurate and may in some cases identify measurements in the order of micron It is important comment that the team has a twist, since the thread (fine) makes it impossible to identify when it is applied too much force and the element of "entered" into the room causing an indentation thus generating a measurement error that makes it appear that it is lower than the real, can be found inside micrometers outer arc deep, deep, all contacts have extremely hard to prevent heat-treated to "give" to pressure from the screw (simple machine). Caliper or gauge .- This tool is very popular and you can almost say that it is irreplaceable in the manufacture of any part, manages an assessment of one tenth of a millimeter, of course it can be found in inches or in both systems units, is made up of four "legs" arranged in pairs around the front of the others, serve to measure the upper inner and outer measure are lower, you can also identify a stem that goes out the back, which serves to measure depths, also identified two scales, a principal depends on the application and a secondary located in the moving part of the latter being the instrument with zero on the main denotes the main measure and the place where the lines overlap between primary and secondary level, marks decimal measurement. clock .- The device consists of a cover, similar to that of a clock which distinguishes one primary and one secondary level, at the bottom of the front panel can identify a stem that enters and leaves the device and equipped with probe at the bottom, the same that moves according to the roughness or unevenness in one piece, is indispensable for use to identify the appropriate support, they are properly lined up, eventually is equipped with magnets that allow for easy mounting and measures variations according to a previously reported value by the operator..