HSS Twist Drill Bits -Trouble Shooting Guide
Publish Time: 2018-08-09 Origin: Site
Trouble shooting guide-twist drills | |||||
• Irregular hole size | • Chipping of corner edge | ||||
• Low position accuracy | • Chipping of cutting edge | ||||
• Hole perpendicularity | • Abnormal wear on corner part | ||||
• Bad cylindrical accuracy | • Large wear and chipping, crushing of the chisel edge | ||||
• Poor surface finish | • Chipping of margin | ||||
• Bad cylindrical shape
| • Margin built-up | ||||
• Tang breakage | |||||
• Noise of chattering | |||||
• Chip rolled around the drill | |||||
• One side wear | |||||
Hole | |||||
Type of trouble | Reasons for the trouble | Solutions | |||
Hole expansion | Run out of drill when attached to the machine | Check holder and/or select another one | |||
Loose hold | Check run out after fixing to the chuck | ||||
Non-symetric point angle | Regrind correctly | ||||
Different lip height | Check preciseness after reground | ||||
Run out of chisel edge |
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Irregular hole size | Non-symetric point angle | Regrind correctly | |||
Large lip height | Check precision after regrind | ||||
Run out of chisel edge |
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Margin wear is large |
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Large run out after attached to the machine | Check holder and select another one | ||||
Loose hold | Check run out after fixing to the chuck | ||||
Low work holding rigidity |
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Feed rate to high | Decrease feed rate | ||||
Not enough lubrication | Use drill with an oil hole | ||||
Low position accuracy | Large run out when attached to the machine | Check holder and/or select another one | |||
Large spindle run out | Check run out after fixing to the chuck | ||||
Run out when cutting material | Select more rigid tool and machine | ||||
Increase work clamping rigidity | |||||
Select a low cutting resistance thinning | |||||
Use centering | |||||
Work piece should be horizontal | |||||
Use a drill bush | |||||
Low alignment accuracy (for lathing) | Check alignment | ||||
Hole perpendicularity | Excessive tool wear | Regrind | |||
Low position accuracy | Increase position accuracy (EX-Gold drill) | ||||
Non-symetric point angle | Regrind correctly | ||||
Large lip height | Check precision after regrinding | ||||
Run out of chisel edge |
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Not enough drill rigidity | Increase drill rigidity | ||||
Drilling surface is not horizontal | Work piece must be horizontal | ||||
Poor alignment (for lathing) | Make a center hole. Check alignment | ||||
Bad cylindrical accuracy | Non-symetric point angle | Regrind correctly | |||
Large lip height | Check precision after regrinding | ||||
Run out of chisel edge |
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Large run out after attached to machine | Check hole and/or select another one | ||||
Loose hold | Check run out after fixing to the chuck | ||||
Low work holding rigidity |
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Relief angle is too large | Regrind correctly | ||||
Low drill rigidity | Use carbide drill or larger web drills | ||||
Poor surface finish | Poor regrinding | Take off all the wear | |||
Not suitable coolant for the material | Change supply method; increase volume | ||||
Not enough coolant | Select higher coolant quality | ||||
Large run out after attached to machine | Check holder and/or select another one | ||||
Loose hold | Check run out after fixing to the chuck | ||||
Feed rate is too high | Reduce feed rate | ||||
Excessive tool wear | Regrind correctly | ||||
Build up on margin is too large | Select a coated tool | ||||
Chip packing | Select suitable drill (wide flute, high helix oil hole drill). Change cutting conditions (feed rate or adopt step drilling) | ||||
Bad cylindrical shape | Non-symetric point angle | Regrind correctly | |||
Large lip height | Check precision after regrinding | ||||
Run out of chisel edge |
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Large margin wear |
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Feed rate is too low | Increase the feed rate | ||||
Drill | |||||
Type of trouble | Reasons for the trouble | Solutions | |||
Drill breakage | In accurate machine | Increase the rigidity of machine, drill and work clamping | |||
Work material deformation | |||||
Relief angle is too small | Regrind correctly | ||||
Feed rate is too high | Decrease the feed rate | ||||
Excessive tool wear | Regrind | ||||
Chip packing | Select suitable drill (wide flute, high helix oil hole drill). Change cutting conditions (feed rate or adopt step drilling). | ||||
Difficulty entering the material | Select high rigid tool & rigid machine | ||||
Increase work clamping rigidity | |||||
Select a low cutting resistance thinning | |||||
Use centering | |||||
Work piece should be horizontal | |||||
Use bush drill | |||||
Chipping of corner edge | In appropriate tool material | Choose suitable tool material | |||
Uneven hardness distribution on the work material | Iso static treatment | ||||
Change tool, material & cutting conditions, machining method (EDM) | |||||
Cutting or feed speed is too high | Reduce cutting speed or feed | ||||
Not enough coolant | Change lubrication method | ||||
Large run out after attached to machine | Check holder and/or select anothre one | ||||
Loose hold | Check run out after fixing to the chuck | ||||
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Relief angle is too small | Regrind correctly | ||||
Tool material is not suitable | Choose suitable tool material | ||||
Cutting speed or feed is too high | Reduce cutting speed or feed | ||||
Abnormal wear on corner part | Tool late regrinding | Regrind after a shorter time of use | |||
Bad alignment (for lathe turning) | Check/adjust the alignment | ||||
Cutting speed too high | Decrease the cutting speed | ||||
Point dimensions are not suitable | Select correct point dimensions | ||||
Tool materials not suitable | Choose suitable tool material | ||||
Coolant is not suitable | Change coolant | ||||
Feed rate is too large | Decrease feed rate | ||||
Point dimensions are not suitable | Select correct point dimensions | ||||
Tool materials is not suitable | Choose suitable tool material | ||||
Relief angle is too small | Increase relief angle | ||||
Bush diameter is too small | Select correct bush diameter or select drill with chip breakers | ||||
Chip packing between drill & bush | |||||
High heat generation due to large wear on the cutting edge | Regrind | ||||
Lubrication is insufficient | Change lubrication method | ||||
Coolant is not suitable | Change coolant | ||||
Bad chip ejection | Change drill or the cutting conditions | ||||
Ductile material | |||||
Tang breakage | Shank slippage due to some kind of defect | Take off the defect by honing the surface | |||
Defect of the inner surface of morse taper holder | Change holder or correct the surface of morse taper holder | ||||
Low accuracy of regrinding | Regrind correctly | ||||
Relief angle is too big | Grind a smaller relief angle | ||||
Low rigidity of the tool | Use drill with high rigidity | ||||
Low extended and curly chips | Change drill and cutting conditions | ||||
Chips are stubbed in the flute | |||||
One side wear | Large run out after attached to machine | Check holder and/or select another one | |||
Check run out after fixing to the chuck | |||||
Bad alignment (for lathe turning) | Check/adjust the alignment |