High Speed Machining Precision Tooling - Indobiz.biz

Shrink Fit:
The High Accuracy
Toolholder of Choice
Requirements in the mold industry are much more precise than general
machining, so more attention must be paid toward the selection of the
appropriate toolholder in regards to its features and benefits
Within the last 10 years, the
acceptance and integration
of shrink fi t toolholders in the
mold and die industry has continued in
aiding all world-based mold shops in
remaining globally competitive.
Toolholding for milling machines in
general had often been overlooked by
most manufacturing facilities throughout
the world especially Asia.
However, it was the mold and die
industry that was really the fi rst segment
of the manufacturing market to look for
more precise toolholder options. Due to
numerous inherent benefi ts, shrink fi t
toolholders have predominately become
the high accuracy toolholder of choice
for the mold and die market.
The Challenge
As the mold and die industry in Asia
has become much more of a globally
competitive market, the need to reduce
expensive labor intensive practices has
become an absolute necessity for shop
owners. The goal for most shops is to
reduce or completely eliminate polishing
or spotting time on their molds. This
can be accomplished in numerous
ways including the use of EDM sinker
machines, hard milling of steel or cutting
closer to net shape from the beginning
of the machining process.
In order to address this challenge, the
mold and die shops have been forced to
look at their entire process. For example,
choosing the correct machine tool for the
job is no longer the only consideration. It
is important to investigate and decide on
the appropriate machine control, CAD/
CAM software package, toolholders and
cutting tools in order to complete the job
most effi ciently
The Toolholder Solution
When looking for toolholder solutions for
any type of machining, it is always good
to fi rst focus on three main features that
a toolholder must bring you:
1. Rigidity
Rigidity comes from suffi cient
taper contact and proper clamping
of the toolholder in the machine tool
spindle.
2. Accuracy
Accuracy comes from minimal
run-out at the cutting edge of the
cutting tool.
3. Balance
Balance comes from a balanced
assembly of the toolholder (including
all accessories such as pull-studs)
and cutting tool combination.
However, the requirements in the mold
and die industry are much more precise
than general machining, so more
attention must be made toward the
selection of the appropriate toolholder
for the job.
For example, a mold shop often must
think of the following:
• Geometry of toolholder to avoid
collisions with the workpiece. In
regards to the EDM process,
electrodes must be machined
accurately and effi ciently. Often
times, deep ribs are required in
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indometalworking news Vol. 2 / 2008