Workshop Technology
Extrusion

Consists of pressing the metal inside a chamber to force it out by high pressure through an orifice which is shaped to provide the desired form of the finished part
Is used for reducing the diameter of round bars and tubes by rotating dies which open and close rapidly on the work
Is used to improve fatigue resistance of the metal by setting up compressive stresses in its surface
Is extensively used for making bolts and nuts

ANSWER DOWNLOAD EXAMIANS APP

Workshop Technology
Piercing is an operation of cutting

A hole (other than cylindrical) in a sheet of metal by the punch and the die
A flat sheet to the desired shape
A number of holes evenly spaced in a regular pattern on a sheet of metal
A cylindrical hole in a sheet of metal by the punch and the die

ANSWER DOWNLOAD EXAMIANS APP