Somta - page 86

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(e) Possible Cause
Mis-alignment of the tap and the hole.
Solution
Care must be taken to align the tap with the hole before starting
to tap.
(f) Possible Cause
Incorrect rake angle
Solution
Use the recommended tap for the material.See page 51/54.
Torn threads in the tapped hole
(a) Possible Cause
The flutes are clogged by chips.
Solution
Use a spiral point or a spiral flute tap.
(b) Possible Cause
Distortion of the walls in a thin walled workpiece.
Solution
Use a multi-fluted tap.
(c) Possible Cause
The threads on the tap are broken.
Solution
Use a tap which is in good condition.
(d) Possible Cause
Lack of/or the wrong type of lubricant.
Solution
Apply an adequate supply and the correct type of lubricant to
the cutting area.See page 63/65.
(e) Possible Cause
Using the incorrect or unsuitable tap for the material.
Solution
Use the recommended tap for the material.See page 51/54.
(f) Possible Cause
Tap hitting the bottom of the hole.
Solution
Allow sufficient clearance at the bottom of the hole.
(g) Possible Cause
Incorrect rake angle.
Solution
Use the recommended tap for the material.See page 51/54.