(1) _Drawing:_ Stretching a piece of metal in one or more directions
either by hammering, or pulling, or rolling, is called drawing. In the
blacksmiths' shop the term drawing always means a decrease in the size
of a cross section of the piece and an increase in the length.
(2) _Bending:_ Bending means making the metal take a shape from a
straight line. It may be made into a circle or curved or bent at right
angles.
(3) _Twisting:_ In the process of twisting no change is made in the
axis of the piece. The faces of the piece are changed; as for instance,
when you twist a piece of paper holding one end fast and turning the
other in the direction of its axis.
_Upsetting:_ Upsetting means increasing the thickness of a piece of
iron by shortening its length.
_Forming:_ Forming is the process of giving a piece of iron shape,
either by hammering or by using some forming machine; for example, the
bulldog.
_Welding:_ Welding means joining two pieces of iron together by heating
them to the right temperature and hammering or pressing them together.