# Relationship between grinding resistance and contact area

July 25, 2019

Which kind of grinding resistance may be greater under the same workpiece and grinding wheel. Face grinding or cylindrical grinding

Looking at the figure below, we can intuitively know that the answer is: A face grinding.

For the circle of the same diameter, has a larger contact area with the face and a smaller contact area with circle.

By calculation formula, the result is also that the contact area of face grinding is greater than that of cylindrical grinding.

 Grinding wheel size Workpiece Diameter (mm) Grinding wheel speed (m/min) Workpiece speed (m/min) Amount of feed (mm) Contact arc length(mm) Contact area(mm2) Diameter(mm) Thickness (mm) Cylindrical grinding 355 32 50 3600 36 0.01 0.669 21.397 510 100 300 1800 18 0.01 1.388 138.811 Internal grinding 25 20 35 2000 20 0.01 0.945 18.895 75 38 100 1800 18 0.01 1.749 66.476 Face grinding 205 19 2000 20 0.01 1.446 27.476 510 100 1800 18 0.01 2.281 228.090

# Contact Arc Length=(1±v/V）√amount of feed/(1/grinding wheel diameter±1/workpiece diameter)

Contact area=contact arc length * grinding wheel thickness

Therefore, the contact area of the face grinding is larger, and the grinding resistance is also larger than that of the cylindrical grinding. (Only see the contact area, all other conditions are the same).

Knowing the size of the contact area is related to the grinding resistance. How can it help with grinding?

If the same grinding wheel is applied to grinding with different contact areas, there will be the following grinding differences:

 Cylindrical grinding Face grinding small Contact area large small Grinding Impedance large small heat large

This difference has a great influence on the grinding result, especially the resistance is high and easy to heat. So, the grain size of the grinding wheel needs to be adjusted.

Therefore, differences in grinding conditions can affect the choice of grinding wheel.