N26
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Technical Guidance /
References
Troubleshooting for Drilling
Failure Cause Basic Remedies Remedy Examples
Drill Failure
Excessive Wear on
Cutting Edge
· Inappropriate cutting
conditions.
· Use higher cutting speeds. ·
Refer to the upper limit of the recommended conditions listed the Igetalloy Cutting Tools Catalogue.
· Increase feed rates. ·
Refer to the upper limit of the recommended conditions listed the Igetalloy Cutting Tools Catalogue.
·
Unsuitable cutting fluid.
·
Reduce pressure if using internal coolant.
·
1.5 MPa or below (external coolant if hole depth is L/D = 2 or less).
· Use cutting fluid with more lubricity. · Use JIS A1 grade No. 1 or its equivalent.
Chisel Point
Chipping
· Off-centre starts.
· Reduce feed rate at entry point.
· f=0.08 to 0.12mm/rev
·
Pre-processing to ensure flat contact surface.
· Use endmill to produce flat surface.
·
Equipment and/or work
material lacks rigidity.
·
Change cutting conditions to reduce resistance.
· Increase v
c
and decrease f (reduce thrust).
· Improve work material clamp rigidity.
· Cutting edge is too
weak.
· Increase size of chisel width. · Set chisel width from 0.1 to 0.2 mm.
·
Increase amount of honing on cutting edge.
·
Make thinning section of central area 1.5x current width.
Chipping On
Peripheral Cutting
Edge
· Inappropriate drilling
conditions.
· Decrease the cutting speed. ·
Refer to the lower limit of recommended conditions listed in the Igetalloy Cutting Tools Catalogue.
· Reduce feed rate. ·
Refer to the lower limit of recommended conditions listed in the Igetalloy Cutting Tools Catalogue.
·
Unsuitable cutting fluid.
· Use cutting fluid with more lubricity. · Use JIS A1 grade No. 1 or its equivalent.
·
Equipment and/or work material lacks rigidity.
· Improve work material clamp rigidity.
· Cutting edge is too
weak.
·
Increase amount of honing on cutting edge.
·
Make peripheral cutting edge 1.5x current width.
·
Reduce the amount of front flank angle.
·
Reduce the amount of front flank angle by 2° to 3°.
·
Peripheral cutting edge starts cutting first
· Increase margin width (W margin). · Increase margin width by 2 to 3x current width.
· Cutting interrupted
when drilling through
workpiece.
· Reduce feed rate. ·
Refer to the lower limit of recommended conditions listed in the Igetalloy Cutting Tools Catalogue.
·
Increase amount of honing on cutting edge.
·
Make peripheral cutting edge 1.5x current width.
·
Reduce the amount of front flank angle.
·
Reduce the amount of front flank angle by 2° to 3°.
Margin Wear
·
Inappropriate drilling conditions.
· Decrease the cutting speed. ·
Refer to the lower limit of recommended conditions listed in the Igetalloy Cutting Tools Catalogue.
· Unsuitable cutting
fluid.
· Use cutting fluid with more lubricity. · Use JIS A1 grade No. 1 or its equivalent.
· Increase coolant supply. ·
If using external coolant, change to internal coolant supply.
· Latent margin wear.
·
Early regrind to ensure adequate back taper.
· Regrind margin damage to 1 mm or less.
·
Unsuitable tool design.
· Increase amount of back taper. · Make back taper 0.5/100.
· Reduce margin width. ·
Decrease margin width to two-thirds of current width.
Drill Breakage
· Chip build-up.
·
Use optimal cutting conditions and tools.
·
Refer to the table of recommended conditions in the Igetalloy Cutting Tools Catalogue.
· Increase coolant supply. ·
If using external coolant, change to internal coolant supply.
·
Collet clamp lacks strength.
· Use collet with strong grip force.
· Replace collet chuck if damaged.
· Use collet holder one size bigger.
·
Equipment and/or work material lacks rigidity.
· Improve work material clamp rigidity.
Unsatisfactory Hole Accuracy
Oversized Holes
· Off-centre starts.
· Reduce feed rate at entry point.
· f=0.08 to 0.12mm/rev
· Decrease the cutting speed. ·
Refer to the lower limit of recommended conditions listed in the Igetalloy Cutting Tools Catalogue.
·
Pre-processing to ensure flat contact surface.
· Use endmill to produce flat surface.
· Drill bit lacks rigidity.
· Use optimal drill type for hole depth. · Refer to the Igetalloy Cutting Tools Catalogue.
· Improve overall rigidity of drill. · Large web with comparatively small flute.
· Drill bit has run-out
· Improve drill clamp precision. · Replace collet chuck if damaged.
· Improve drill clamp rigidity. · Use collet holder one size bigger.
·
Equipment and/or work material lacks rigidity.
· Improve work material clamp rigidity.
Poor Surface Finish
· Inappropriate cutting
conditions.
· Increase cutting speeds. ·
Refer to the upper limit of the recommended conditions listed the Igetalloy Cutting Tools Catalogue.
· Reduce feed rate. ·
Refer to the lower limit of recommended conditions listed in the Igetalloy Cutting Tools Catalogue.
·
Unsuitable cutting fluid.
· Use cutting fluid with more lubricity. · Use JIS A1 grade No. 1 or its equivalent.
Holes Are Not
Straight
· Off-centre starts. · Increase feed rates. ·
Refer to the upper limit of the recommended conditions listed the Igetalloy Cutting Tools Catalogue.
· Drill is not mounted
properly.
· Improve drill clamp precision. · Replace collet chuck if damaged.
· Improve drill clamp rigidity. · Use collet holder one size bigger.
·
Equipment and/or work
material lacks rigidity.
· Improve work material clamp rigidity.
· Select a double margin tool. · Refer to the Igetalloy Cutting Tools Catalogue.
Unsatisfactory Chip Control
Packing Of Chips
· Inappropriate drilling
conditions.
· Increase cutting speeds. ·
Refer to the upper limit of the recommended conditions listed the Igetalloy Cutting Tools Catalogue.
· Increase feed rates. ·
Refer to the upper limit of the recommended conditions listed the Igetalloy Cutting Tools Catalogue.
·
Poor chip evacuation.
·
Increase the amount or pressure of coolant applied if using internal coolant.
Long Stringy Chips
· Inappropriate drilling
conditions.
· Increase feed rates. ·
Refer to the upper limit of the recommended conditions listed the Igetalloy Cutting Tools Catalogue.
· Increase cutting speeds. ·
Refer to the upper limit of the recommended conditions listed the Igetalloy Cutting Tools Catalogue.
·
Cooling effect is too strong.
·
Reduce pressure if using internal coolant.
·
Keep pressure 1.5 MPa or lower if using internal coolant.
· Dull cutting edge. · Reduce amount of edge honing. · Reduce to around two-thirds of current width.
Technical Guidance
Tool Failure and Remedies
Drilling Edition