Application guidelines
Tool and cutter grinding is a very wide field with a large spectrum of different machine tools that vary greatly in spindle power output and overall system rigidity. Broadly speaking, one can distinguish between two major processes: reciprocating grinding for resharpening and creepfeed grinding for producing cutting tools from solid blanks. Creepfeed processes demand, among other things, very rigid machine tools and a high level of spindle drive power. Particularly in mass production processes of cutting tools, creepfeed has become the
dominant process for the grinding of flutes (chip grooves).
Selection of wheel type, diameter and rim section
If the machine and the tool design permit, preference should be given to a cup wheel rather than a dish wheel as cup wheels are more rigid and stable: |
The wheel diameter should be chosen as large as possible, machine tool permitting, and given that the surface speed can be adjusted in accordance with the application and the safety requirements.
The rim section's width "W" has a considerable influence on the grinding result. A wider rim section results in a better surface finish. It generates, however, more grinding pressure and frictional heat and must be chosen in a softer grade than a narrow rim section for the same task.
Chip removal in side grinding with cup wheels takes place within the contact area "Ak". Wide rim sections generate high temperatures in the contact zone and, therefore, reduce the material removal rate. The contact area "Ak" should be chosen as small as possible. |
Advantages of narrow contact width "W"
-wheel is very free cutting and aggressive
-cool cutting
Disadvantages of narrow contact width "W"
-Shorter toollife
-Higher surface roughness |
| Side grinding results in large contact areas "Ak". Cup wheel shapes such as 6A2 and 6A9 are very rigid. If dealing with heat-sensitive materials, preference should be given to the 6A9 as its contact area "Ak" is smaller than that of wheel shape 6A2. Also, the smaller the contact area, the better the self-sharpening effect of a wheel. |
Rim width and depth of grinding on tool
The active rim width should be smaller than the actual depth of grinding on the tool to be ground. If this is not the case, a step on the rim section will be generated.
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