The hardness of the grinding wheel refers to the difficulty of the abrasive grains on the surface of the grinding wheel falling off under the action of grinding force.The hardness of the grinding wheel is soft, which means that the abrasive grains of the grinding wheel are easy to fall off, and the hardness of the grinding wheel is hard, indicating that the abrasive grains are difficult to fall off. (Important! The hardness of the grinding wheel does not refer to the hardness of the grinding wheel)
The hardness of the grinding wheel and the hardness of the abrasive are two different concepts. The same kind of abrasive can be made into grinding wheels of different hardness, which is mainly determined by the performance and quantity of the bonding agent and the manufacturing process of the grinding wheel. Significant differences in the grinding wheel and the cutting is "self-sharpening", select the hardness of the wheel, in fact, choose sand is not self-sharpening wheel, hoping also sharp abrasive particles do not fall off too early, and do not blunt the Fall off.
The general principle for selecting the hardness of the grinding wheel is to use a hard grinding wheel in order to prevent the abrasive from falling off prematurelywhen processing the soft metal . When processing hard metals , in order to timely remove the blunt abrasive particles to expose new abrasive grains with sharp edges (ie, self-sharpness), a soft grinding wheel is used. The former is because when grinding soft materials, the working abrasive grains of the grinding wheel wear very slowly, and do not need to be detached too early; the latter is because when grinding hard materials, the working abrasive grains of the grinding wheel wear faster and need to be faster. Update.
In the case of fine grinding, in order to ensure the grinding accuracy and roughness , a slightly harder wheel should be used . When the workpiece material has poor thermal conductivity and is prone to burns and cracks (such as grinding hardalloys ), the selected grinding wheel should be softer .
Grinding wheel hardness grading and code
Hardness level | Code |
Big class | Small level |
so soft | so soft | D. E. F. |
soft | Soft 1 | G |
Soft 2 | H |
Soft 3 | J |
Medium soft | Soft 1 | K |
Soft 2 | L |
in | Medium 1 | M |
Medium 2 | N |
Medium hard | Medium hard 1 | P |
Medium hard 2 | Q |
Medium hard 3 | R |
hard | Hard 1 | S |
Hard 2 | T |
Super hard | Super hard | Y
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