The document discusses various types of rolling mills used to roll metals, including two high, three high, two high reverse, four high, multi, universal, and planetary rolling mills. It describes the basic setup and functions of two high, three high, two high reverse, four high, and cluster rolling mills. Additionally, it mentions tandem, universal, and planetary rolling mills as well as shape rolling operations like ring and thread rolling. Finally, it lists some common defects in rolled metal parts.
3. TYPES OF ROLLING MILLS
Two high rolling mill
Three high rolling mill
Two high reverse rolling mill
Four high rolling mill
Multi rolling mill
Universal rolling mill
Planetary rolling mill
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4. TWO HIGH ROLLING MILL
Two rolls
Rolls rotate in a constant
direction
Both cold and hot working
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5. THREE HIGH ROLLING MILL
Three rolls
Upper and lower rolls are drive
rolls
Middle rolls rotates by friction
Rolling of two continuous
passes in a rolling sequence
without reversing the drive
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6. TWO HIGH REVERSIBLE ROLLING MILL
Rolls can rotate in both
direction
Reducing the handling of hot
metal in between the rolling
passes
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7. FOUR HIGH ROLLING MILL
It has a roll stand with four
parallel rolls one above the
other
The top and the bottom rolls
rotate in opposite direction as
do the two middle rolls
The two middle are smaller in
size than the top and bottom
rolls which are called backup
rolls for providing the necessary
rigidity to the smaller rolls
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8. CLUSTER ROLLING MILL
It is a special type of four high
rolling mill in which each of the
two working rolls is backup by two
or more of the larger backup rolls
for rolling hard in materials
It may be necessary to employ
work rolls of a very small diameter
but of considerable length
In such cases adequate of the
working rolls can be obtained by
using a cluster mill
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9. TANDEM ROLLING MILL
It is a set of two or three stands of
roll set in parallel alignment
So that a continuous pass may be
made through each one
successively with change the
direction of material
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10. UNIVERSAL ROLLING MILL
Metal is reduced to desired shape
by both horizontal and vertical
rolls
Sheets, plates, slabs and beams
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11. PLANETARY ROLLING MILL
Requiring large reduction
Number of free rotating wheels
are fixed to a large backup roll
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