Grinding wheel hardness selection

First, the choice of ordinary grinding wheel 1, the choice of hardness depends mainly on the workpiece material being ground, grinding efficiency and machining surface quality.

Hardness refers to the difficulty of the grinding wheel to fall off under the action of the external force. In order to meet the requirements of different workpiece material grinding processing, the grinding wheel is divided into different hardness grades (see Table 3).

The grinding wheel is selected hard, the blunt abrasive grains are not easy to fall off, the grinding wheel is easy to be blocked, the grinding heat is increased, the workpiece is easy to burn, the grinding efficiency is low, and the surface quality of the workpiece is affected; the grinding wheel is too soft and the abrasive particles are still falling off sharply. , Increase the loss of grinding wheel, easy to lose the correct geometry, affect the accuracy of the workpiece. Therefore, the choice of hardness of the grinding wheel should be properly considered, and it should be comprehensively considered according to factors such as the contact area of ​​the grinding wheel and the workpiece, the shape of the workpiece, the grinding method, the cooling method, and the type of the bonding agent of the grinding wheel. The following wheel hardness selection principles are for reference:

a. When grinding soft materials, choose harder grinding wheels; when grinding hard materials, choose soft grinding wheels;

b. When grinding soft and tough non-ferrous metals, the hardness should be selected softer;

c. Grinding poor thermal conductivity materials should be selected softer grinding wheel;

d. Grinding wheel hardness should be selected softer when face grinding than circumferential grinding;

e. Under the same grinding conditions, the hardness of the resin-bonded grinding wheel is 1 to 2 smaller than that of the ceramic-bonding grinding wheel.

f. When the rotation speed of the grinding wheel is high, the hardness of the grinding wheel can be selected from soft 1 to 2 small grades;

g. Grinding with a coolant is one to two orders of magnitude higher than the hardness of the wheel during dry grinding.