Humans have practiced metal working for centuries, perfecting techniques depending on the type of metal being worked. 

Presently, metal working can be divided into two main categories. 
– Hot working
– Cold working

The terms “hot” and “cold” do not refer necessarily to the temperature with which the metals are worked, rather when the processing temperature of the mechanical deformation of the metal is above recrystallization temperature, it is considered a hot working. Otherwise, it is cold. If this relationship is lower than 0,3° it is considered “cold”, if it is greater than 0,6° it is considered “hot”. If it is between the two values, it is considered “lukewarm”.

There are three hot technical processes: forged (forging), casting, and moulding, while cold processes like deep-drawing are used typically for aluminium sheets and stainless steel. This allows the metals to then be bent and shaped. 
The finish consists of a series of steps carried out by tools and machines where it is possible to perform turning, milling, bottlenecking, filing, reaming, and planning.

In the next Focus On we will explore more deeply the “cold” and “hot” techniques.

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