Schools Training

Know Your Metals

13 SEP 2012
Career Path : Apprenticeships

They conduct electricity. They can store and transfer heat. They can be bent and stretched. They can reflect light. They form the support of our industrial structures. They compose most of the earth’s natural elements. They are metals.

For over 8,000 years, mankind has been mining and processing metals. Beginning with gold, we made ornament, jewelry, and coins. With the later discovery of copper, the first tools and weapons were forged. Then came lead, the most malleable metals discovered up to date. Its use became widely popular during the Roman era as piping, and was born the fields of plumbing, sanitation and irrigation.

Welding is the art and process of joining metals together through forging—melting them down to near liquid heats, which when cools can harden two pieces together into a single solid piece. It dates back to the Bronze Age when copper was the main metal used for welding. It then became increasingly important during the Iron Age, as iron and steel took over as the primary metal.

It is impossible today to become a welder without first taking the time to understand the basics of metals themselves and metallurgy. This emphasis on metal education is akin to knowing about food before simply learning recipes, or studying maps before simple memorizing directions. A thorough training and welding apprenticeship will cover the basics of many metals, including the following:


Copper is very ductile, meaning it can be easily reshaped by being pulled or stretched. This is useful for turning metals into a long, thins sheets or into wire form. It is also excellent for conducting heat and electricity. Its combined ductility and conductivity make it ideal for electrical wires. It is also has a natural color that is not grey, ranging from yellow to orange to red, which is why it is popular in ornament. For welding, it binds very easily with other metals.


Steel is made of a combination of iron and other elements, often carbon. Depending on which element and the amount, its degree of ductility and malleability can vary, and therefore different kinds of steels are used for different kinds of welding. When combined with higher levels of carbon, for example, it is extremely hard and durable, but this has an inverse effect on its ductility.


This is an extremely low-density metal, which means it is light weight. It is also one of the most common metals found in the earth’s crust, likely because it is harmless to and unharmed by other flora and fauna in its environment. One of its strengths is its resistance to corrosion, and thus lasts a long time. It is a relatively easy metal to weld with, so long as the conditions have been well-cleaned and as oxide-free as possible.

These three metal descriptions are just some of the basic things a welder should know. There are in fact a great many variations in welding between metals and sub-categories of metals. In training for a career by doing a steamfitter or sheet metal worker apprenticeship, one learns to take the ABCs of these metals and forge them into a meaningful language of metallurgy.

Visit Mohawk College for information on welding, sheet metal worker, or steamfitter apprenticeships.