PRESS TOOL ACCESSORIES:


DIE SET:
It is the unit assembly which incorporates a topshoe
and bottom shoe, two or more guide pillars and guide
bushings.
Advantages: 1) It aligns the punch and die members.
2) It reduces the setup time in the press
to a minimum.
3) This facilitates resharpening of punch
and die without removing from
the dieset.
TOP SHOE:
This is the upper part of the dieset which contains
guidebushings and punch holding assembly. It is directly
fastened to the press ram with the help of shank.
BOTTOM SHOE:
This is the lower part of the dieset which contains
guide pillars.
It is generally mounted on the press bed. The die block
is mounted on the bottomshoe.
PUNCH:
Punch is the male part of the die assembly,
which is directly or indirectly moved by and fastened
to the press ram.
Punches are made from good grade of tool steel
or high carbon high chromium steel material and it is
hardened.
Punch is the master of piercing.
DIE:
Die is the female part of the die assembly, which
is mounted on the lower shoe.
Dies are made from tool steels or high carbon high
chromium steel and it is hardened.
Die is the master of blanking.

BACKUP PLATE:
Backup plate or pressure plate placed between the
top plate and punch holder plate.It is a hardened one.
It is used to prevent the punch making any impression
on the soft top plate.
The plate distributes the pressure over a wide area
and the intensity of pressure on the punch holder is reduced
to avoid crushing.Backup plates are made from OHNS
materials and carbon steels(C45) and it is hardened and
ground parallel.
(OHNS-Oil hardened non-shrinkage steel)
The thickness of the backup plate depends upon
the stock thickness.

For upto 2mm stock thickness, 3mm thickness
backup plate is used.
For about 3mm stock thickness, 6mm thickness
backup plate is used.

PUNCH HOLDER PLATE:
It is fastened to the top plate through the backup plate.
It is used to hold the punch correctly.These plates are made
from mild steel material.

GUIDE PILLARS AND GUIDE BUSHINGS:
Guide pillars are mounted on the bottom shoe and
guide bushings are mounted on the top shoe.Both they are
press fitted on their plates. Pillar and bush have a slide
fit to them. They are help in obtaining alignment of the
punch and die. These are made from carbon steels and
hardened and ground.



STRIPPER PLATE:
This plate is mounted on the die plate.It is called
as fixed stripper plate. A channel is provided in this plate
for feeding the metal strip.It is used to stripout the strip
from the punch during the return stroke of the press.
It is also helps to correctly guide the punch into the
dieopening. In some cases, it is mounted to the punch
assembly. It is called as spring loaded stripper.