Decoding Kotlin - Your guide to solving the mysterious in Kotlin.pptx
shet mtl-.ppt
1. Internal
Sheet metal is available in flat pieces or as a coiled
strip.
The coils are formed by running a continuous sheet of
metal through a roll slitter.
The thickness of the sheet metal is called its gauge.
The gauge of sheet metal ranges from 30 gauge to
about 8 gauge.
Different metals that can be made into sheet metal,
such
as aluminum, brass, copper, steel, tin, nickel and titani
um.
3. Internal
SHEET METAL WORKING
In this simply metal formed into thin and flat pieces.
It is one of the fundamental forms used in metalworking, and
can be cut and bent into a variety of different shapes.
Countless everyday objects are constructed of the material
Low cost parts with very high rates at faster rates.
Thicknesses can vary significantly, although extremely thin
thicknesses are considered foil or leaf, and pieces thicker than
5 mm (0.25 in) are considered.
4. Internal
For decorative uses, important sheet metals include silver, gold,
and platinum
Sheet metal has applications in car bodies, airplane wings, medical tables,
roofs for buildings and many other things.
5. Internal
SHEARING
It is a cutting operation used to remove a blank of
required dimensions from a large sheet. To
understand the shearing mechanism, consider a metal
being sheared between a punch and a die, Fig.
6. Internal
Sheet Metal Forming processes
Shearing processes -- processes which apply shearing
forces to cut, fracture, or separate the material.
Forming processes -- processes which cause the metal
to undergo desired shape changes without failure,
excessive thinning, or cracking. This includes bending
and stretching.
Finishing processes -- processes which are used to
improve the final surface characteristics.
7. Internal
Major processing parameters in shearing are shape
and materials for punch and die, speed of punching,
lubrication, clearance between punch and die .
The clearance between the punch and the die plays
an important role in the determination of the shape
and quality of the sheared edge.
There is an optimum range for the clearance, which is
2 to 10% of the sheet thickness, for the best results.
8. Internal
SHEET METAL OPERATIONS
It is the cheapest & fastest way of the complete manufacture of a
component.
sheet metal is considered to be a plate with thickness less than about 5mm.
Classification of press tool operations:
Stresses induced Operations
1.Shearing Blanking, shearing, Piercing, Trimming,
Shaving, Notching ,Nibbling etc.,
2. Tension Stretch forming
3. Compression Coining, sizing, ironing, hobbing
4. Tension & Compression Drawing, Spinning, bending,
forming, embossing
9. Internal
Shearing starts as the punch presses against the sheet metal.
At first, cracks form in the sheet on both the top and bottom edges (marked T
and T', in the figure).
As the punch descends further, these cracks grow and eventually meet each
other and the slug separates from the sheet.
A close look at the fractured surfaces will reveal that these are quite rough
and shiny.
11. Internal
PUNCHING & BLANKING
It is a process in which the punch removes a portion of material from the
larger piece or a strip of sheet metal.
If the small removed piece is discarded, the operation is called punching(or
Piercing), whereas if the small removed piece is the useful part and the rest
is scrap, the operation is called blanking.
13. Internal
CUTTING (SHEARING) OPERATIONS
In this operation, the work piece is stressed beyond its
ultimate strength.
The stresses caused in the metal by the applied forces will
be shearing stresses. The cutting operations include:
Punching (Piercing) Blanking
Notching Perforating
Parting Lancing
Slitting Shaving
Trimming Fine blanking
15. Internal
NOTCHING:
This is cutting operation by which metal pieces are cut
from the edge of a sheet, strip or blank.
PERFORATING:
This is a process by which multiple holes which are
very small and close together are cut in flat work
material.
PARTING:
Parting involves cutting a sheet metal strip by a punch
with two cutting edges that match the opposite sides
of the blank.
or shearing sheet in to 2/ more pieces.
16. Internal
SHAPING OPERATIONS
IN SHAPING OPERATIONS THE METAL IS DEFORMED
INTO REQUIRED SHAPES BY PUNCH & DIE.
IN FORMING, THE METAL IS DEFORMED OR BENT ALONG A
CURVED AXIS.
VARIOUS FORMING OPERATIONS ARE:
1. EMBOSSING 2. COINING
3. SPINNING 4. SWAGING
1. EMBOSSING:
IT IS A SHALLOW FORMING OPERATION WHICH USES A
MATCHED PUNCH & DIE. THE THICKNESS OF WORK PIECE IS
UNIFORM, AND IS INTENDED FOR DUPLICATING OF THE PATTERN
ON EITHER SIDES OF THE SHEET METAL. IT IS USED FOR
DECORATIVE SHEET WORK AND TO OBTAIN THE IMPRESSIONS OF
DESIRED FORM.
18. Internal
2. COINING:
COINING IS SQUEEZING OPERATION IN WHICH THE METAL
FLOWS INTO THE CAVITY BETWEEN THE PUNCH & DIE. IT IS
EMPLOYED FOR MAKING COINS, MEDALS AND SIMILAR
ARTICLES.
