Be familiar with Machining of mechanical parts I know it in my friends ， The shape of guide rail is right angle ， Add anti dumping and force sealing structure or rectangular guide rail 。 Stay Parts processing plant ， Their worktable （ Base ） And guide rails in all directions are made of natural granite materials 。

　　 According to Parts processing and customized service center Introduce ， Natural granite has the following advantages ：

　　1、 Natural granite has experienced natural aging for hundreds of millions of years ， Stable performance 。 After saw 、 Milling 、 Drill 、 Study 、 After polishing and other processing, the internal stress is also very small 。

　　2、 At present ， Granite can be processed to high precision ： Straightness can be achieved 1um/m， Flatness can be double O Level requirements 5um/（1000mm*1000mm）。

　　3、 The linear expansion coefficient of granite is very small ， Generally speaking （5.7～7.34）X0.000001℃–1，〖 Cast iron is (8.7～11.1)X0.000001℃–1， Chromium steel 11.7X0.000001℃–1〗， Therefore, the heating deformation is very small 。

　　4、 Granite is lighter than cast iron 1.5 Times ， Wear resistance is cast iron 5～10 Times 。

　　5、 Granite has good vibration resistance ， The internal damping coefficient is larger than that of steel and cast iron 15 Times 。

　　6、 Granite has diamagnetism ， No magnetization and adhesion ， Moisture resistance, not easy to rust ， Convenient maintenance 。

　　7、 Stress damage of granite ， Only local damage will occur without affecting the flatness and straightness around it 。

　　8、 At present ， The processing of granite is simple ， And it can be bonded and formed ， Firm and rigid ， Convenient for design ， Shape should be as simple as possible ， In order to reduce Machining of mechanical parts Cost 。

　　9、 Granite brittle ， But the material cost is low 。 China abounds in granite ， But only the density is greater than 2.6～3g/cm3、 Water absorption less than 0.2％ Person ， It's suitable for making Parts processing plant Worktable and guide rail of precision instrument 。

　　 According to Parts processing and customized service center Introduce ， Mount Tai blue and white granite is one of the best granite in the world ， Gabbro ， Gray black fine grain structure ， Study Black after tossing 。 Its main physical properties ： Density 3.07g/cm3， Compressive strength 26.2kgf/cm2， Bending strength 37.48kgf/cm2， Shore rebound hardness is 79.8， The modulus of elasticity is (1.2～1.28)×104kgf/mm2。 Therefore ， Granite is the best material for worktable and guide rail of high precision instrument 。

　　 At present ， Some Parts processing plant Granite or Person Artificial granite for precision machine tools Base And guide rail ， Switzerland Studer Company S Series high precision grinder ， Britain Granfield Company OAGM2500 Large precision machine tool 。