SURFACE PROCESSING MARKS
Even the most delicately machined surfaces are rough. Without the surface roughness, it would be impossible to separate these surfaces from each other since there would be no air between two superimposed surfaces with zero roughness values. Although the roughness is not zero, it can be reduced. Smoother surface treatments improve quality, but pahalıdır.yüzey processing signals triangles juxtaposed Until recently Turkey (DIN 3141) were shown with. This demonstration is still used by some manufacturers and projectors who have not been able to update itself.

The degree of roughness in Turkey, mostly in the DIN 3142 norm now being used is indicated by the RA value.
From time to time, in projects coming from America or Canada, the surface treatment value may also be encountered in ASA 46-1 norm. The values ​​in the ASA norm are 40 times the values ​​in the DIN3142 norm.
The Ra value is the value that gives the average of the negative and positive elevation and depression dimensions of the surface in thousandths of a millimeter (μm). This value is written on the surface treatment marks and the manufacturer is informed about how the part should be processed. As the Ra value decreases, the manufacturing cost increases rapidly as can be seen in Figure 1. Example: If the unit machining cost of a surface machined with +/- 0.7 mm precision is one, +/- 0.1 mm. The unit processing cost of a surface processed with precision is 10 times, and the unit processing cost of a surface processed with +/- 0.01 mm precision is 30 times. For this reason, if it is not necessary, surface treatment with Ra value should be used as much as possible in our projects and productions. Here, without going into details, we just gave the meaning of the surface treatment signs, how the relevant surface was obtained and where these surfaces are used in the table below. TABLE: SURFACE -