Обший каталог Yamawa 2016 - 2017 - страница 846

24. The mechanism for a tap to cut oversize on an internal thread
1. Run out, misalignment and tap cutting in non perpendicular to holes Over-cutting at radial direction
Description of products


Tool run out during tapping Misalignment during tapping Tapping a non-parallel or non-perpendicular
thread to the axis of the hole.
Holder needs to be Axis of tapping process Verification of
holder holder holder holder
adjusted. Tapping with and bored hole should prepared hole
run out can be observed be lined up correctly. condition.
and checked when idle The use of adjustable
running. holder with floating
features will reduce this
Lateral force problem.
Solutions

misalignment

Run out


Excessive cutting in radial direction causes oversized internal threads. Since tapping proceeds along bored hole,
in the depth of hole, oversize cutting is minimized, that is, oversize cutting in the beginning of the hole and
normal cutting in the depth of the hole.

Excessive-cutting in the radial direction Normal internal threads


Not Go gauge

Over sized Normal Not Go
internal threads internal gauge internal threads
at the beginning Not Go gauge
of the bore threads


2. Using a tap not suitable for the operation or a tap with dull Over-cutting caused by galling and excess cutting
cutting edge may cause galling and result in over-cutting.
Using an incorrect tap for a specific workpiece material Tapping process with dull edge
can cause problems
Wear Welding Chipping
Select the correct Tap Flank
Straight fluted tap
Spiral fluted tap
Spiral pointed tap
Roll tap
Parallel
Wear wear Welding Chipping
Selection of correct taps suitable for material being
tapped is strongly recommended. Solution: Proper use of cutting oil, confirmation of a constant for tool life


Torn threads occur on the thread flanks. If this Incomplete
thread
situation gets worse, there occur large thread
Over-cutting caused by
collapses or incomplete threads finally bringing out galling and excess feeding
oversized internal threads. Incomplete
Depending on the condition of collapsed threads thread
such trouble tends to occur discontinuously as
NOT-GO gouge enters.
Information
Technical


Special attention needs to be taken so that random
inspection should not miss this kind of trouble. Incomplete
thread
Not Go gauge


Technical-71
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