The document describes a project report on the design of a common bending tool for two sheet metal components (left and right). It discusses the history of metal shaping tools and introduces press tools and their types like blanking, piercing, bending, etc. It also covers topics like strip layout, types of strip layout arrangements, factors that affect strip arrangement, die design parameters and calculations. The key objectives are to maximize material utilization, reduce production costs, and increase part output through an efficient strip layout and tool design.

1. PROJECT REPORT ON
A PROJECT REPORT ON
COMMON BENDING TOOL DESIGN
FOR TWO SHEET METAL COMPONENTS(LEFT&RIGHT)
GANDHI INSTITUTE FOR TECHNOLOGY,
BHUBANESWAR
PREPARED BY –
GAURAV KUMAR SINGH
KISHAN KUMAR NAIK
JAGANNATH SAHU
DEEPAK KU. DALBEHERA
GUIDED BY-
PROF.RADHAKRISHNA SAHU
PROJECT HEAD-
PROF.KHITISH KUMAR
DASH

2. CONTENT:
 HISTROY
 INTRODUCTION
 TYPES OF PRESS TOOL
 MAJOR OPERATION BY COMPOUND TOOL
 THEORY
 DEFINITION OF STRIP LAY OUT
 TYPES OF STRIP LAY OUT
 STRIP ARRANGEMENT
 FACTORS DEPEND UPEN STRIP ARRANGEMENT
 CALCULATION
 DIFFERENT PARAMETERS
 DIE DESIGN
 REFERENCE

3. HISTROY:-
Historically, metal was shaped by hand using
a hammer. Later, larger hammers were
constructed to press more metal at once, or to
press thicker materials. Often a smith would
employ a helper or apprentice to swing
the sledgehammer while the smith concentrated
on positioning the work piece.
Adding windmill or steam power yielded still larger
hammers such as steam hammers. Most modern
machine presses use a combination of electric
motors and hydraulics to achieve the necessary
pressure. Along with the evolution of presses
came the evolution of the dies used within them.

4. INTRODUCTION
 PRESS TOOL:
A machine press, commonly shortened to press,
is a machine tool that changes the shape of a
work piece.
 Press tools are commonly used
in hydraulic and mechanical presses to
produce components at a high
productivity rate. Generally press tools are
categorized by the types of operation
performed using the tool, such
as blanking,piercing, bending, forming, forging,
trimming etc. The press tool will also be
specified as blanking tool, piercing tool,
bending tool etc.

5. TYPES OF PRESS TOOL
 Blanking tool
 Piercing Tool
 Cut off tool
 Parting off tool
 Trimming tool
 Shaving tool
 Bending tool
 Forming tool
 Drawing tool
 Progressive tool
 Compound tool

6.  Blanking tool
 When a component is produced with one single punch and die where the entire
outer profile is cut in single stoke is called Blanking.
 Blanking is the operation of cutting flat shapes from sheet metal.
 The hole and metal remained after blanking operation is discarded as a waste.
 Size of blank or product is the size of the die & clearance is given on punch.
 It is a metal cutting operation.
 It is fast process and generally used for medium and mass production volumes.
 It is cheapest process in manufacturing.
 Piercing Tool
 Piercing involves cutting of clean holes with resulting scrape slug. The
operation is often called piercing, In general the term piercing is used to
describe die cut holes regardless of size and shape. Piecing is performed in a
press with the die. The piercing tool is used to pierce the holes as secondary
tool such as after bending of component etc.
 Cut off tool
 Cut off operations are those in which a strip of suitable width is cut to lengthen
single. Cut-off tools can produce many parts. The required length of strip can
be cut off for bending and forming operations using this tool.

7.  Parting off tool
 Parting off is an operation that involves two cut off operations to
produce blank from the strip. During parting some scrape is
produced. Therefore parting is the next best method for cutting
blanks. It is used when blanks will not rest perfectly. It is similar to
cut off operation except the cut is in double line. This is done for
components with two straight surfaces and two profile surfaces.
 Trimming tool
 When cups and shells are drawn from flat sheet metal the edge is
left wavy and irregular, due to uneven flow of metal. This irregular
edge is trimmed in a trimming die. Shown is flanged shell, as well
as the trimmed ring removed from around the edge. While a small
amount of Material is removed from the side of a component in
trimming tool.
 Shaving tool
 Shaving removes a small amount of material around the edges of
a previously blanked stampings or piercing. A straight, smooth
edge is provided and therefore shaving is frequently performed
on instrument parts, watch and clock parts and the like. Shaving
is accomplished in shaving tools especially designed for the
purpose.

8.  Parting off tool
 Parting off is an operation that involves two cut off operations to
produce blank from the strip. During parting some scrape is
produced. Therefore parting is the next best method for cutting
blanks. It is used when blanks will not rest perfectly. It is similar to
cut off operation except the cut is in double line. This is done for
components with two straight surfaces and two profile surfaces.
 Trimming tool
 When cups and shells are drawn from flat sheet metal the edge is
left wavy and irregular, due to uneven flow of metal. This irregular
edge is trimmed in a trimming die. Shown is flanged shell, as well
as the trimmed ring removed from around the edge. While a small
amount of Material is removed from the side of a component in
trimming tool.
 Shaving tool
 Shaving removes a small amount of material around the edges of
a previously blanked stampings or piercing. A straight, smooth
edge is provided and therefore shaving is frequently performed
on instrument parts, watch and clock parts and the like. Shaving
is accomplished in shaving tools especially designed for the
purpose.

9.  Progressive tool
 Progressive tool differs from the stage tool by the following
aspect, In progressive tool the final component is obtained
by progressing the sheet metal or strip in many stages. In
each and every stages the component will get its shape
stage by stage the full shape will be obtained at the final
stage.
 Compound tool
 The compound tool differs from progressive and stage tool
by the arrangement of punch and die. It is a inverted tool
were blanking and piercing takes place in a single stage
and also blanking punch will act as piercing die.
 Combination tool
 In combination tool two or more operations will be
performed simultaneously such as bending and trimming
takes place in a single stage. IN combination tool two or
more operations such as forming, drawing, extruding,
embossing may be combined on the component with
various cutting operations like blanking, piercing,
broaching and cut off takes place.

10. MAJOR OPERATION BY COMPOUND TOOL
 BLANKING
Blanking is the operation of cutting a flat shape from the
sheet metal. The article punched out is called the
“blank” and is the required product of the operation. The
material remaining after blanking left is behind is
discarded as waste.
 PIERCING
It is a cutting operation by which various shaped holes
are made in the sheet metal. Piercing is similar to
blanking except that here the hole the desired product,
the material cut out to form the hole being waste.

12. CLEARANCE:-
It is defind as the difference between the punch and die
in one side. Mathematically
C/2=Die size-Punch size
In case of blanking ,
Punch Size<Actual size of the component ,i.e.
Punch Size =Actual size – Clearance
Die size = Actual size
In case of Piercing ,
Die size>Actual size of the component ,i.e.
Die Size =Actual size + Clearance
Punch size = Actual size

14. STRIP LAYOUT:-
 Strip layout plays an important role
especially in the case of the design of the
press tool. Strip decides the economic
utilization of the work piece and helps in
the decrease of cost of the job and
reduction in the production time by
increasing the number of components.

15. DEFINITION OF STRIP LAY OUT
The first step in strip layout is defining the strip.
This process involves naming the strip assembly
and the strip part and defining the width and
height of a station, the project shortcut, the
number of stages, and an offset before and after
the strip. You can specify a prefix for the name
that is generated for parts placed inside the strip
assembly. Parts include instances of the article
and stamp reference parts.

16. ECONOMY FACTOR
 Stock material consservation is a decisive factor in means
should be tried to attain this without sacrificing the piece part.
Economy of any strip layout in percentage is fount out by the
following formula.
 Economy factor(E) in %=(area of the blank *number of rows*
100)/(width of the strip*pitch)
A minimum economy of 60% should be aimed .
 The position of the blank in the strip decides the economy
factor.

17. TYPES OF STRIP LAY OUT:-
 Single row one pass layout:-
This is the most popular way of laying out the strip.The blanks are arranged
in a single row.The strip is passed through the tool only once to punch out the
blanks from it.
There are two possible ways of laying out this strip.
- Narrow run
- wide run
Wide run is more desirable due to the following reasons.
Shorter advance distance of the strip promotes easy feeding.
More blanks could be prduced from a given length of strip compared to
narrow run.Therefore a fewer number of strips are to be handled to produce a
given number of blanks.
Narrow run is used when the grain direction of the piece part has
importance.

18. DOUBLE ROW LAY OUT:-
 Higher economy can be attained by positioning the blanks in
double rows.
 Gang dies:-
A gang die consists of two or more similar sets of tool members
so as to produce two or more number of components during a
single stroke of the press ram.
 A gang die eliminates the cumbersome process of double pass.
the higher tool cost will be off set by higher rate of
production.Gang dies are not recommended for very complex
work.
 Angular layout :-
Some piece parts require to be laid out in an angular position
to make the lay out more economical.

19. WHAT IS STRIP LAYOUT ARRANGEMENT?
 Strip layout is important to have economy of press
tool operation.
 Scrap strip layout gives an idea on the
positioning of various punches, stops and pilots.
It ensures the ideal location of blanks in the stock strip.
 Several trial layouts have to be made to confirm the
maximum percentage of utilization of stock strip. The
goal should be to have at least 75% utilization.
 Strip-layout design is an important step in the planning stage
of sheet metal work on progressive die. It is an experience-
driven activity and the quality of strip-layout is highly
dependent on the knowledge and skill of die designers

20. STRIP ARRANGEMENT:-

22.  Press tool design types may be categorized by layout as well
as by motif or style of pattern.The term layout refers to the
arrangement of motifs in the framework of the design plane.
 Unlike a painting or drawing, which is designed in relation
to its boundaries or edges, the elements in a textile design
are designed in relation only to each other.
 There are no boundaries, when the pattern is printed it will
continue over yards and yards of cloth. For a textile design
to be reproduced on fabric, it must eventually be developed
into one standard unit containing a specific arrangement of
the desired motifs.
 This one unit,called a repeat, will be repeated across the
width and length of the fabric in a continuous manner.

23. FACTORS DEPEND UPON STRIP LAYOUT
ARRANGEMENT:-
 Maximum material utilization in obtained.
 The choice of an efficient strip-layout is an
important step during die design, because as
only the optimum layout can reduce wastage of
the strip material.
 Reduce the overall cost of production.
 Increases number of production of products.
 It also reduces company's production cost.
 It also saves time of production.

24. CALCULATION:-
For the strip layout and design, We have to
consider the following parameters. i.e,
A. Net weight of the component
B. Gross weight of the component
C. Metal loss
D. % metal loss
E. Cutting force
F. Press capacity
G. Press Tonnage
H. Die cavity

26. BASIC DIE COMPONENTS
1 -shank
2 -shank holder
3 -backing plate
4 -punch holder
5 -punch
6 -guide post bushing
7 -guide post
8 -stripper
9 -guide rail
10-die block
11-die shoe

27. PART DETAILS OF COMPOUND TOOL

28. DIE DESIGN:-
 Overall dimensions of the die block will be
determined by the minimum die wall thickness
required for strength and by the space needed for
screws and dowels and for mounting the stripper
plate. wall thickness requirements for strength
depend upon the thickness of the stock to be cut.
Sharp corners in the contour may lead to cracking in
heat treatment and so require greater wall thickness
at such points.
 Only two dowels are provided in each block or
element that requires accurate and permanent
positioning. these should be spaced as far apart as
possible for maximum locating effect, usually near
diagonally opposite corners.

29.  Screws and dowels are preferably located
about 1.5 times their diameters from the
outer edges or blanking contour.
 For very thin materials, 12.7 is sufficient but,
except for temporary tools, finished
thickness is seldom less than 22mm,which
allows for blind screw holes
Stock thickness(mm) Die thickness(sq.
mm)per ton
Stock thickness(mm) Die thickness(sq.
mm)per ton
2.5 0.8 15.2 3.8
5.1 1.5 17.8 4.19
7.6 2.2 20.3 4.6
10.2 2.8 22.9 4.8
12.7 3.3 25.4 5.1

30.  Die thickness also calculated according to the
blank required.
 Die block thickness should be a minimum of
19.1mm for a perimeter between 76.2mm to
101.6mm.
 For longer perimeters, die block thickness
should be 31.75mm.
 Die blocks are seldom thinner than 22.2mm
finished thickness to allow for grinding and blind
screw holes.
 If the perimeter of the blank is approximately
177.8mm ,a die block thickness of 38.1 is
specified of 6.4 mm grinding allowance.

31. MARGIN:-
 There should be a minimum of 32mm margin around
the opening of the die block
 On die blocks up to a78mm square use a minimum up
two M10 cap screw and two 10mm dowels
 For blanking heavy stock, use cap screws M14 and
dowels 14mm.
 Die must not If special alloy steels are used then die
thickness can be decreased.
 The critical distance A , between the cutting edge and
the die border must be 1.5 to 2 times the die thickness
for smaller dies. But for larger dies it may be 2 to three
times.
 be thinner than 7.6mm

33. CLEARANCE:-
 Clearance is generally taken as 10% of the strip
thickness. Such as if the thickness is 1.64,then
clearance should be 1.64×10=0.16 per each side. If the
blank is to be the size of the die then clearance is given
on the punch side.
 PUNCH DIMENSIONING
 The determination of punch dimension has been
generally based on practical experience.
 For piercing t he dia of punch can be calculated from
the following formula;
 4St÷sd=1

34. Where s=unit compressive stress on the punch
S=unit shear stress on the stock
T=stock thickness
D=dia. of punch holes
 Diameters of the most hole are greater than the stock
thickness, but a value of ratio d:t of 1:1 is
recommended
 The maximum allowable length of the punch can be
calculated from the following formula
L=(πd÷8 )×(E÷S)×(d^0.5÷t)
Where
E= modulus of elasticity

35. ADVANTAGES:-
 SMALL WEIGHT OF FABRICATED PARTS.
 HIGH PRODUCTIVITY OF LABOUR.
 HIGH VOLUME, LOW-COST PRODUCTION.
 PREDICTABLE STRENGTH CHARACTARISTICS.
 UNIFORMITY OF PARTS.
 LOW COST MATERIAL.
 LESS LABOUR-CONSUMING.
 LESS WASTE PRODUCT WILL OCCURS.

36. APPLICATION:-
 IT IS USED IN AEROSPACE INDUSTRIES,
HOUSE HOLD EQUIPMENTS, AUTOMOBILE
PARTS,SHIP PARTS,ELECTRONIC APPLIANCES.
 THE BEST EXAMPLES ARE DAILY USED SAVING
BLADE,DRAWING CLIPS,COLDRINK BOTTLE
CAP & CAP OPENER,CANE CLIP, ETC.

37.  Metal Cutting And Tool Design By B.J.RANGANATH.
 Mechanical Engineering Design By JOSEPH SHIGL
EY & CHARLES MISCHKE.

Engineering Design By GEORGE DIETER AND LIND
A
SCHMIDT.
 Fundamentals Of Tool Design By David Spitler, Jeff
Lantrip, John Nee and David A Smith.
REFERENCES:-