19
YOUR GLOBAL CRAFTSMAN STUDIO
2
3
2006 ~
2002 ~
Roughly ten years after the ZET1 drill was
born, the solid carbide drill had become
widespread across the industry, and
various products including those of other
companies had appeared in the market.
New developments were also demanded
of the ZET1 and the development team
had run up against a wall as to what
types of improvement should be made.
It was then that the general manager
of development gave the following
advice: “Go and hand cut holes in bars
of soap until you find an answer.” We
spent several days thereafter, using
both Mitsubishi and competitors’ drills,
single-mindedly drilling a huge amount
holes in soap by manually rotating
them. As a result, we discovered many
things through the sensations we felt
in our hands, such as where the point
of resistance begins and how chips are
discharged. This led to a shift in concept
from the ZET1 drill’s linear cutting edge
to a curved type. We thus explored how to
realize a wavy type cutting edge that no
one had ever seen before. The inspiration
for this curved shape came suddenly
fromamomentwhile cookingwhenusing
a food processor to chop ingredients.
Inspired by the bold curves on the blades
of the food processor and aftermuch trial
and error, we ultimately came up with the
WSTAR solid carbide drill with its unique
wavy cutting edge.
Through the wavy edge and new flute
geometry we succeeded in minimizing
the size of chips and this enabled a more
efficient discharge. In addition a newly
developed point shape ensured excellent
concentricity and positional accuracy
of holes. Furthermore, we were able
to extend tool life by adopting VP15TF
Miracle coating. These features ensured
that the WSTAR drill series, launched in
2002, became recognised for its accuracy
and long tool life and has become a
product that is still favoured by many
customers today.
TECHNOLOGY ARCHIVE
TECHNOLOGY ARCHIVE
Beyond the ZET1 drill, the origin of
theWSTAR series
The ongoing evolution of the
WSTAR drill series
Part
Part
TheWSTARdrill has further evolved since
2006 in response to the needs of the
market. The series of drills has expanded
and now includes the general-purpose
MWE/MWS drills designed primarily for
carbon and alloy steels. In addition, the
MNS, MHS, MMS and MCS drills that
are designed specifically for machining
aluminium alloy, high-hardened steel,
stainless steel and CFRP materials
respectively, have also been launched.
Amongst the highlights that are available
today are also the super-long type
drills for machining deep holes with an
aspect ratio of up to L/D = 30. Each of
these products embodies technologies,
originality and ingenuity that only
Mitsubishi Materials could achieve. An
example of this originality is the MNS
drill that was developed for machining
aluminiumalloys. To lubricate the precise
spot near the centre of the drill where
chipstendtoadhere,furtherimprovement
of the coolant flowwas required. Straying
beyond the conventional two-hole drill,
we collaborated with the manufacturing
technology group and created a drill with
four coolant holes, the first drill of its kind
in the world. Then, taking this technology
further, we developed and released the
MVE/MVS general-purpose solid carbide
drill series in 2013 by employing TRI-
Cooling technology to create an originally
shaped coolant hole that requires
extremely high precision. By taking an
innovative approach to increasing the
flow rate, we succeeded in enhancing
cooling performance, lubricity, discharge
of chips and the overall performance of
the drill itself just because of the design
of the coolant hole. Long tool life against
a wide range of work materials was
also realised by applying a PVD coating
(DP1020) that was designed specifically
for drills. WSTAR is indeed the perfect
solid carbide drill series for the new
generation of engineering needs.
GP/AP/VP
2002
2014
MZS
MPS
MWS
Newwavycutting
edgedesign
TRI-Cooling technology
VP
MIRACLESIGMA
MIRACLESIGMA
MNS
MQS
MVS
DP1020DP1021
Historyof thesolidcarbidedrill (standardsize)
Productivity& tool life
Newmaterial
New
shape
Further innovation
