MAURBHANJ SCHOOL OF ENGINEERING

BARIPADA : 757107 , ODISHA

CHAPTER – 05

TOPIC- PRESS WORK

BRANCH- MECH.

SEMISTER- 3^rd

SUBJECT- PRODUCTION TECHNOLOGY

FACULTY- ER KHAGESWAR PATRA

Estd:.1994

Press work

• Press working may be defined as, a manufacturing process by which various components are made from sheet metal. This process is also termed as cold stamping. The machine used for press working is called a press.

Press Operations

Press operations are broadly classified in to twogroups:

• Cutting operations,
• Non cutting operations (Forming operations)

Cutting operations and forming operations

Cutting operations

• Blanking: is the operation of cutting a flat shape from sheet metal. The product punched out is called the "blank" and the required product of the operation the hole and the metal left behind is discarded as waste.
• Punching or Piercing:It is a cutting operation by which various shaped holes are made in sheet metal. Punching is similar to blanking except that in punching, the hole is the desired product. The material punched out from the hole being waste.

Cutting Operations

Cutting Operations

• Trimming: This operation consists of cutting unwanted excess of material from the periphery of previously formed acomponent.
• Shaving: The edge of a blanked part are generally rough, uneven and un square. Accurate dimensions of the part are obtained by removing a thin strip of metal along the edges.

Cutting Operations

• Notching: This is cutting operation by which metal pieces are cut from the edgeof the sheet, strip or blank.
• Perforating:This is a process by which multiple holes are very small and closetogether are cut in a flat sheet metal.
• Slitting:It refers to the operation of making incomplete holes in a work piece.
• Lancing:This is a cutting operation in which a hole is partially cut and then one side is bent down to form a sort of tab. Since no metal is actually removed and there will be no scrap.

Non Cutting Operations

• Bending:In this operation; the material inthe form of flat sheet or strip is uniformlystrained around a linear axis which lies inthe neutral plane and perpendicular it's thelength wise direction of the sheet or metal.
• Drawing:This is a process of forming a flatwork piece into a hollow shape by meansof a punch which cause the blank into adie cavity.
• Squeezing:Under the operation, the metal is caused to flow to all portions of a die cavity under the action of compressive forces .

Press Terminology

Press Terminology

• Bed:The bed is the lower part of the press frame that serves as a table to which aBolster plate is mounted.
• Bolster Plate:This is a thick plate secured to the press bed, which is used for locating and supporting the die assembly. It is usually 5 to 12.5 cm thick.
• Die Set:It is unit assembly which incorporates a lower and upper shoe, two or moreguide parts and guide part bushings.
• Die Block:It is a block or a plate which contains a die cavity.
• Lower Shoe:The lower shoe of the a die set is generally mounted on the bolster plate of a press. The die block is mounted on the lower shoe, also the guide post are mounted on it.

Press Terminology

• Punch:This is male component of a die assembly, which is directly or indirectlymoved by and fastened to the press ram or slide.
• Upper Shoe:This is the upper part of the die set which contains guide post bushings.
• Punch Plate :The punch plate or punch retainer fits closely over the body of the punch and holds it in proper relative position.
• Back up Plate:Back up plate or pressure plate is placed so that intensity of pressure does not become excessive on punch holder. The plate distributes the pressure over a wide area and the intensity of pressure on the punch holder is reduced to avoid crushing.
• Stripper:It is a plate which is used to strip the metal strip from cutting a non cutting Punch die. It may also guide the sheet.

Types of Presses

Types of Presses

Types of Presses

Types of Presses

Types of Presses

Basic Cutting Action

Compression

Shearing

Breakage

Thank you

CREATED BY: ER KHAGESWAR PATRA