BENDING, FORMING AND DRAWING DIES

1.  Define neutral axis?

The axis which separates the portions of tension and compression is known as

“Neutral axis” or “Neutral layer”.

2.  What is bend angle?

Bend angle is the angle between the two extreme positions of bend radius.

3.  List down the types of bending dies?

Edge bending

 V - Bending

U – Bending

4.  What is spring back in bending?

The tendency of the metal tries to resume its original position causing a decrease in bend angle known as spring back,

5.  What does spring back cause in bending?

Spring back is caused by a larger bend radius.

6.  Spring back depends on the following factors.

Material type

Thickness

Hardness

Bend radius

7.  What does meant by bending allowance?

It is also called spring back allowance. Spring back allowance is defined as the tendency of sheet metal to change the shape from final shape.

8.  What is meant by coining?

The process of pressing the metal in a die to allow the metal to flow into the space on the die face is known as coining.

9.  Mention the application of coining process.

Metal buttons

Table wares

Jewellery

10. What are the advantages of coining process?

Excellent surface finish can be obtained.

More close tolerances can be achieved.

11. Define deep drawing?

Deep drawing is the manufacturing process of forming sheet metal stock, called

blanks, into geometrical or irregular shapes which are more than half their diameter in depth.

12. Define redrawing process.

The process of deepening the cup after the first draw is known as redrawing.

13. What is meant ironing?

The process of reducing wall thickness and lengthening of the cup is known as ironing.

14. List down the type of drawing dies?

Single action dies

Double action dies

15. What are the methods of holding pilots?

Direct pilots

Indirect pilots

16. Classify indirect pilots.

Acron type or spherical type.

Flatted end type.

17. Define ductility.

Ductility is the ability of the material to undergo a change in shape without fracture.

18. How can we define drawing speed?

Drawing speed is defined as the velocity at which the punch travels into the drawing die during the drawing process.

19. What is the purpose of stock-stop?

It is used to stop the die at a required distance. It avoids over penetration of die in a materials.

20. What are draw die inserts?

Draw die inserts are small tooling segments attached to form a shape during drawing operations.