Working with Metals: Iron, Steel, Stainless

In the long and arduous process of restoring a vehicle, it is likely that you have stumbled across a baffling array of materials used to construct your ride. From the heavy-duty components in the engine compartment to the flimsy trim in your interior, you will find that metals comprise a large percentage of your car. The older a vehicle is, the more metal (and less plastic) it contains. This is because metals have long been the first choice in strength and durability. Today, of course, advanced plastics and composite materials are starting to replace metal in parts of modern vehicles, but it is obvious that metal still plays an irreplaceable role in the construction of the automobile.


What follows is an overview of the advantages of certain metals over others in various situations you may encounter during a resto project. In certain situations, aftermarket restoration parts are available in different grades of metal, or in different metals altogether, so it helps to understand their differences. If you are truly lucky (or unlucky), you may have a vehicle so rare or expensive that you can't get parts any other way than by having them made out of a particular metal.


Metallurgy is a science and its own engineering field with thousands of types and grades of materials. Even within a certain type of metal, there can be a broad band of different grades of the same material with varying heat, strength, wear and hardness ratings. To keep from being overrun with obscure and mind-numbing facts, we'll break this overview down into three basic parts. In part one, we will discuss iron, steel and stainless steel, since these three closely related materials are all carbon-iron alloys. They all come from iron ore and vary in characteristics depending on the alloy, or mixture of certain elements. Then we'll follow up in the next section with non-ferrous metals and aluminum. Lastly, we will cover exotic materials.

The Iron Fist
The first and most basic group would be iron itself. Iron may make you think of steam engines and archaic machinery, but various forms of cast iron can make for extremely durable parts, if used in the right places. It tends to be very rigid, resisting deformation even when very heavy loads are placed upon it.


Iron is also very good at resisting wear. When properly lubricated, it can look new even when it has been used for thousands of hours.