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TAPPING PROBLEMS: CAUSESAND SOLUTIONS
Damaged tap threads in the hole
(a) Possible Cause
Mis-alignment of the tap with the hole before starting to tap.
Solution
Care must be taken to align the tap with the hole before starting
to tap.
(b) Possible Cause
The tap is too dull
Solution
Use a tap which is in good condition.
(c) Possible Cause
Work hardened skin in the drilled hole.
Solution
Work hardening can be avoidedwhen drilling by using the correct
speeds,and coolants.
Use serial taps.
(d) Possible Cause
Incorrect rake angle
Solution
Use the recommended tap for the material.
Poor finish of the thread
(a) Possible Cause
Using the incorrect tap.
Solution
Use the recommended tap.
(b) Possible Cause
The drilled hole is too small.
Solution
Use the recommended drill size.
(c) Possible Cause
The tap is too dull.
Solution
Use a tap which is good condition.
(d) Possible Cause
Insufficient number of threads on the lead.
Solution
Use a tap with the correct lead.
