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TAPS Troubleshooting USER GUIDE

Problem Cause Solution
Incorrect tap (cutting geometry unsuitable for application). Use tap selected from the relevant material group.
Faulty alignment. Ensure that the tap is correctly aligned with the core hole axis.
Tapped hole
oversized Tap jamming. Improve lubrication and direction of coolant
Adjust cutting speed.
Incorrectly reground tap (lead tip is not concentric). Regrind tap.
Incorrect tap (cutting geometry incorrect for application). Use a tap from the relevant material group.
Check feed rate programming and/or pitch of leading
Stripped threads Spindle speed and feed rate are not synchronized.
spindle. Use a tapping spindle with axial float (GTI/GTIN).
Insufficient starting pressure exerted on tap (causes peeling). Increase starting pressure.
Bell mouthed Incorrect starting pressure. Use a tapping spindle with axial float (GTI/GTIN).
tapped hole
Incorrect tap (cutting geometry unsuitable
for application). Select tap for the relevant material group.
Unsatisfactory The tap is blunt. Replace or regrind tap.
thread surface
finish Tap badly re-ground. Regrind tap. Check that cutting geometry
is suitable for material.
Incorrect lubricant, concentration or quantity. Ensure the use of a suitable coolant and an ample supply.

Swarf jamming. Check cutting speed. Use alternative tap.
Tap has jammed against bottom of pre-hole. Check hole and thread depths. Drill a deeper pre-hole.
Partial tap
chipping Tap incorrectly reground (lead-in diameter too Ensure that correct dimensions are maintained when regrinding.
short, therefore too few cutting teeth).

Irregular workpiece material structure. Adjust cutting speed. Improve lubricant quality of coolant.
Incorrect cutting speed. Adjust cutting speed to suit workpiece material.
Coolant lacking in lubricating qualities Ensure the use of a suitable coolant and an ample supply.
Excessive and/or quantity. Check that the coolant is reaching the cutting zone.
tap wear
Check pre-hole drilling conditions (drill carefully to reduce
Surface of the pre-hole is compacted.
risk of surface compacting). Check drill cutting edges.
Incorrect tap in use (cutting geometry unsuitable for application). Use tap from the relevant material group.
Centering error. Ensure that axes of tap and pre-hole are aligned.
Blunt tap. regrind tap.
Tap breakage
Use tapping spindle with axial float and
Tap has reached bottom of pre-hole.
slipping clutch (GTI/GTIN).
Pre-hole too small. Check for correct pre-hole size, see pages 428-429.

438 ISCAR