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Fineblanking
Explained in greater detail under fineblanking
process fundamentals, fineblanking can best be described as a cold
extrusion process. Fineblanking is not stamping.
Fineblanking utilizes three concurrent forces to closely control material flow
throughout the process of forming and extruding.
For general guidelines regarding the fineblanking process and material selection,
click here (pdf)
Fineblanking Presses:
MPI has more than 90 presses in its fleet.
The fineblanking presses, 250 tons and below, are mechanical presses. These
presses incorporate hydraulic cylinders to control the stinger pressure and
counter pressure, but main pressure (blanking force) is applied by mechanical
force.
Larger presses, including 250 tons and above, are fully hydraulic presses. In
addition to hydraulic cylinders being used to control stinger pressure and
counter pressure, the main pressure is also applied by a hydraulic force.
Within MPIs press groups from 250 to 800 tons, MPI has several horizontal
presses. These presses operate in a horizontal direction rather than a vertical
direction (up and down). Horizontal presses are a benefit in many heavier gage
applications, as the tool is cleared by gravity rather than by compressed air or mechanical
means.
Similar to our horizontal presses, MPIs 1000 ton presses are tiltable to
aid heavy part ejection.
Fineblanking Dies:
Fineblank dies are extremely robust, precision tools. Fineblank tool components
are all straight sided and typically have clearances of 1/2 of 1% of material
thickness.
Advancements in tool making equipment have been highly beneficial for
tool manufacture. However, the skill required to build precision fineblank
tools remains an art that continues to be passed on to apprentice tool makers
by experienced journeyman.
The most basic fineblank dies are compound dies. These tools produce one or more
components with each stroke of the press.
Comparatively, progressive fineblank dies are more complex tools that are
capable of producing sophisticated components by advancing the production of a
part through several stations within a single die. As parts are formed and cut
within a progressive fineblank die, they are transferred between stations by
the material strip and then cut free in the final station before being
ejected from the tool.
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