Here at Eastwood we’ve always worked to bring industrial and professional quality tools at a DIY price and because of that we get questions from beginners or hobbyists looking to step up their welding and fabrication skills and tools. While it may be a simple answer for someone working in the fabrication trade or a life long welder; the average home hobbyist get confused when we start talking metallurgy. If you’re going down the path of welding and fabrication you need to at least understand what makes up different types of metal. The most common classification is ferrous and non-ferrous metals. What metals are ferrous and what makes them different from non-ferrous? We give you no-nonsense answers below!
What is Ferrous Metal?
Ferrous metal is the most common type of material used during heavy fabrication and in industrial applications. Most everything you can think of is made of ferrous metals including bridges, automobiles, pipelines, fences, and many other uses. Ferrous metal is most simply determined as a material that contains Iron in it’s chemical makeup. This means steels of all types, cast iron, wrought iron, and even stainless steel. In most cases ferrous metals are magnetic and you can quickly determine their classification. Stainless steel is one of the exceptions and is the best as far as durability goes.
Common Types of Ferrous Metals
Mild Steel
Your “basic” steel is mild steel which is an alloy that is made of mostly iron with some carbon added. Pure iron is “soft” and easy to bend, move and manipulate. By mixing in carbon; mild steel is made. Mild steel can be further modified into different classifications. Mild steel has increased strength over pure iron as the carbon in it creates strength; but also makes it slightly harder to manipulate. Mild steel has a high tensile strength that is used in everything from automobile manufacturing to bridge and structure building. Steel can be welded with any welding procedure with no special procedures needed. Normally Mild steel is inexpensive and is the most common ferrous metal used in DIY metal fabrication.
High Carbon Steel
There are varying degrees of carbon steel and the higher the carbon content the stronger and more durable it is. Generally you will need to heat these higher carbon steels to form them and then heat treat to bring the hardness back. High carbon steel has an extremely high carbon to iron content and is one of the most durable types of metal used in industrial applications. This type can be used for anything from tooling like drill bits, cutting blades, springs, high strength wires etc. Carbon steel as a rule of thumb usually has a high carbon count and may be difficult to weld the higher the carbon count. Often in the DIY world “High Carbon” Steel is misidentified when manufacturing or fabricating and in reality you’re working with a medium carbon steel. Medium carbon steels are used commonly in automotive applications, forging, and other manufacturing processes.
Cast Iron
Cast Iron is an alloy mainly made of straight iron with small amounts of carbon and silicone added for hardness and flexibility. Cast Iron tends to be a “brittle” metal and will brake usually before it bends. Cast iron has great heat transfer properties and is commonly used in engine blocks, rear axle housings, cook wear, and other dense applications. Cast Iron can tend to be difficult to repair or weld because of its heat transfer properties and needs to be brought up to temperature before welding and then slowly cooled to avoid cracking in the weld.
Wrought Iron
Unlike a high carbon steel wrought iron has very little carbon in it and is great for forming, bending, and stretching. It was often used in the “old days” but has been phased out over the years other than for pure decorative situations. Most often you see it used in hand rails, window bars, and on antique car restorations for brackets and braces. It is easy to heat and weld but isn’t as strong as other higher carbon steels.
Stainless Steel
Stainless steel while corrosion resistant is still in the ferrous metal family. It is an alloy that is chemically made to have a high resistance to corrosion and is extremely strong. There are many types of stainless steel and they all vary on their strength, scratch resistance, corrosion resistance and more. Most commonly stainless steel is used on vehicles for areas that often rust or corrode quickly like exhaust parts, fasteners, etc. They are also used in industrial applications where cleanliness is necessary like food grade plants and more. Stainless Steel generally needs more care when welding and while it can be welded with a standard MIG welder or the like the filler material needs to match the stainless or it may rust at the weld due to a mild steel filler being introduced to the joint. We like stainless steel for an alternative to chrome on some parts of a custom car like headers or exhaust as it can be polished over and over without chipping or flaking like chrome over time.
Non-Ferrous Metals
Aluminum
Aluminum is probably the most common Non-Ferrous metal most deal with and it is used in a plethora of fabrication, manufacturing, and industrial applications. Much like stainless steel there are many types of aluminum that are produced for different applications and properties. Aluminum is a great conductor of electricity, lightweight, strong, and malleable; but it will oxidize over time. Because pure metal is so soft copper is often added to give it additional strength. Aluminum can also be easily annealed unlike ferrous metals. Most commonly we see 3000 and 5000 series aluminum used for automotive work but 6000 series may also be used for parts that are made for strength and to be machined and not formed.
Zinc
Zinc is is a metal that is commonly used with other metals to make alloys or used in coatings to protect the surface of other metals. One unique property of Zinc is that it isn’t oxidized by the air around us and therefore it is great to use as a coating on other metals or to add corrosion resistance to other metals.
Copper
Copper is most commonly seen in use still in electrical wiring as it is known for how conductive it is and how malleable it is so it can be stretched or formed into thin wires. Copper does oxidize when exposed to Oxygen and will turn green on the surface when oxidizing. Copper can be melted together or brazed to dissimilar metals with the correct welding procedure.
Brass
Brass is an alloy made up of Copper and Zinc. It is used for it’s brilliant color on decorative items like ornaments, buttons, etc. but is also used in electrical fittings and connections for its conductivity properties. Because brass is partly made up of Zinc it has a high corrosion resistance and is often chose to be used in areas where it can’t be serviced or cleaned. Much like Copper brass can me melted together or brazed with dissimilar metals.
If you’re looking to get into metal fabrication or welding Eastwood has you covered. Visit our Metal Fabrication Products HERE.