Drilling solutions
| DRILLING SOLUTIONS | ||
| Problem | Cause | Solutions |
| Borehole is too large | • Feed rate is too high • Chipping blockage • Run-out defect on the drill used • Grinds incorrectly |
• Reduce feed rate • Use the correct tool • Reduce run-out defect as much as possible • Check grinding is correct |
| Burr at borehole exit | • Cutting speed is too fast • Wear limit width exceeded |
• Reduce feed rate • Replace or re-sharpen tools in good time |
| Breakage of the cutting edge | • Unstable working conditions • Incorrect core hole drill • Unstable workpiece clamping • Wear limit width exceeded • Feed rate is too high • Lip clearance angle too great |
• Clear spindle clearance • Use the correct core hole drill • Check workpiece clamping • Replace or re-sharpen tools in good time • Reduce feed rate • Carry out better re-sharpening |
| Fissure in the core | • Impact on the chisel edge • Drill tip too sharp • Feed rate is too high • Lip clearance angle too great |
• Correct cutting speed • Re-sharpen correctly • Reduce feed rate • Re-sharpen correctly |
| Chisel edge wear | • Cutting speed is too low • Insufficient lubricating coolant delivery • Incorrect lubricating coolant composition • Feed rate is too high |
• Correct cutting speed • Ensure good lubricating coolant delivery • Ensure good lubricating coolant composition • Reduce feed rate |
| Built-up edge development | • Insufficient lubricating coolant delivery • Incorrect lubricating coolant composition • Cutting speed is too low • Uncoated tool |
• Ensure good lubricating coolant delivery • Ensure good lubricating coolant composition • Increase cutting speed • Use a coated tool |
| Poor borehole surface quality | • Feed rate is too low • Inaccurate positioning |
• Increase feed rate • Centre borehole in advance |
| Vibrations | • Cutting speed is too high • Feed rate is too low • Unstable workpiece clamping • Run-out error of the core hole drill is too great |
• Reduce cutting speed • Increase feed rate • Ensure stable workpiece clamping • Reduce run-out error |
| Flank wear | • Cutting speed is too high • Feed rate is too low • Clearance angle too small |
• Reduce cutting speed • Increase feed rate • Increase clearance angle |
| Corner wear | • Excessive speed | • Reduce speed to the optimum • Possible increase in feed rate |
| Margin wear | • Cutting speed is too high • Run-out error of the core hole drill is too great • Tool tapering is insufficient • Insufficient lubricating coolant delivery • Incorrect lubricating coolant composition |
• Reduce cutting speed • Reduce run-out error • Use tools that are more tapered • Ensure good lubricating coolant delivery • Ensure good lubricating coolant composition |
| Fluting edge breakage | • Poor chip removal • Drill bit is not stable in the chuck |
• Remove earlier • Ensure that the drill bit is in the chuc |
| Stand length is insufficient | • Incorrect cutting specifications • Unstable workpiece clamping • Insufficient lubricating coolant delivery • Incorrect lubricating coolant composition |
• Ensure cutting specifications are correct • Ensure stable workpiece clamping • Ensure good lubricating coolant delivery • Ensure good lubricating coolant composition |
| Poor borehole surface quality | • Feed rate is too low • Inaccurate positioning |
• Increase feed rate • Centre borehole in advance |
| Vibrations | • Cutting speed is too high • Feed rate is too low • Unstable workpiece clamping • Run-out error of the core hole drill is too great |
• Reduce cutting speed • Increase feed rate • Ensure stable workpiece clamping |
| Flank wear | • Cutting speed is too high • Feed rate is too low • Clearance angle too small |
• Reduce cutting speed • Increase feed rate • Increase clearance angle |
| Corner wear | • Excessive speed | • Reduce speed to the optimum • Possible increase in feed rate |
| Margin wear | • Cutting speed is too high • Run-out error of the core hole drill is too great • Tool tapering is insufficient • Insufficient lubricating coolant delivery • Incorrect lubricating coolant composition |
• Reduce cutting speed • Reduce run-out error • Use tools that are more tapered • Ensure good lubricating coolant delivery • Ensure good lubricating coolant composition |
| Fluting edge breakage | • Poor chip removal • Drill bit is not stable in the chuck |
• Remove earlier • Ensure that the drill bit is in the chuc |
| Stand length is insufficient | • Incorrect cutting specifications • Unstable workpiece clamping • Insufficient lubricating coolant delivery • Incorrect lubricating coolant composition |
• Ensure cutting specifications are correct • Ensure stable workpiece clamping • Ensure good lubricating coolant delivery • Ensure good lubricating coolant composition |