UH-CT | Carbide Taps for Ultra Hard Materials | YAMAWA

Product Features

• The UH-CT is designed for tapping SKD and pre-hardened steel
  50HRC to 63HRC (Max 63).
• It is produced from a ultra fine grain cemented carbide with superior abrasion
  resistance and impact resistance.
• The UH-CT has an improved shank roundness accuracy.
• Recommended tapping length is "Major diameter size x 1.5" or less 5P chamfer for better tool life.
• For the bored hole diameter, the maximum minor diameter of a 6H internal thread diameter maximum value is recommended.

Tapping Data

The figure above is a comparison of the number of tapped holes using a standard carbide tap (N-CT) and a
carbide tap in SKD 11 high hardness quenched steel at 60 HRC. The N-CT tap, had chipped flutes at
8 holes. Compared to the N-CT, the UH-CT was able to process 60 holes in ultra high hardness steel. It is
important to watch for a dull drill as it will cause the taps flutes to wear prematurely. The drilling is
processed at a 6m/min. cutting speed and a 0.04mm/rev. feed which can easily cause work hardening.
・ Bored hole in this test was prepared by using a carbide drill under such condition as could cause no
work-hardening. (cutting speed: 6m/min, feed 0.04m/rev.)

The figure above shows the relationship between the
number of tapped holes and the load meter (%) of
the machine when machining tests are conducted up
to 60 holes with UH - CT tap. The numerical value
of the load meter tends to increase as the number of
tapped holes increase at 50 completed threads. The
cutting edge damage at this point causes the load
meter to raise quickly beyond 50 tapped holes. As
the number of tapped holes progresses further, the
risk of tap breakage is considerable and the load will
increase, so it is recommended to set the life
expectancy at a safe level considering the high
hardness of the steel being processed.