In the metal forging industry, craftsmen often compare the qualities of the two most commonly used metal alloys – wrought iron and cast iron. The conversation even goes as far as pitting one against the other in terms of which one is better.
If you’ve been wondering which material is better for your home renovation project we’re here to help out. We’ll take a look at the difference between wrought and cast iron, compare the two metals’ properties, and look at the advantages of each. We’ll also look at where both iron alloys find their application.
Let’s dive right into it.
What Is Wrought Iron?
Wrought iron derives its name from the archaic past participle of the word “to work”, it literally means worked iron. It was named so, thanks to its incredible flexibility, ideal for creating exquisite ornamentations and twisted designs.
The metal is malleable and stringy, made from semi-infused fairly pure iron beads and iron slag (thanks to which the metal has a grainy texture). Wrought iron contains no more than 0.1% carbon and 1 to 2% slag.
The material is durable, corrosion-resistant, and relatively easily forged through welding. It’s highly refined with up to 99% of its mass being iron. The remaining amount of slag adds to its shock and vibration resistance and eases its processing by blacksmiths.
What Is Cast Iron?
Cast iron is an iron alloy that is formed by reducing iron ore in a blasting furnace. Once the iron ore is melted in the furnace it gets poured into crude ingots, named pigs. This is the form in which the cast iron is usually stored.
Once needed the cast iron pigs are remelted along with metal scrap and alloying elements in cupola furnaces and recast in molds shaped in the desired product.
Cast iron contains more than 2% carbon, along with different amounts of manganese, silicon, sulfur, and phosphorus. Depending on the quantity of each additional element (impurities) the cast iron exhibits different properties and falls under a distinct type.
Among the types of cast iron are cast iron with varying alloying elements (most predominant of which is silicon), gray cast iron, white cast iron, malleable cast iron, and ductile cast iron.
The Difference Between Wrought Iron & Cast Iron
Though both are derived from iron – wrought iron and cast iron are formed differently and exhibit their own distinct physical properties.
How can one tell wrought iron and cast iron apart?
The easiest way to tell them apart is based on the way they are worked with. Wrought iron is heated and then worked on with tools, while cast iron is melted, poured into molds, and allowed to solidify. The different ways these metals are produced (which we pointed out in the previous sections), also influence the wrought iron and cast iron’s strengths and weaknesses.
So let’s look at the two metal alloys’ properties that give them their advantages.
Wrought Iron & Cast Iron Advantages
Compared to wrought iron, cast iron is hard but brittle and very difficult for molding.
It generally doesn’t have much allowance for bending, stretching, or hammering into shape. It’s also harder to cut.
However cast iron has excellent compression strength – perfect for construction projects. It requires little machining (finishing processes), and it’s highly wear-resistant. The material is highly available and comes at a lower cost.
Wrought iron, on the other hand, is made to be manually crafted. It’s very bendable, flexible, and has high fatigue resistance (it can undergo large amounts of deformation before failing).
The material, however, cannot be hardened through heating or quenching. It’s a labor-intensive metal and is more expensive than cast iron.
Wrought Iron & Cast Iron Applications
Both cast iron and wrought iron are arguably two of the most important materials in human history. Thanks to both, some of the most iconic historic monuments have been erected and still stand today.
The famous Eiffel Tower was constructed thanks to 7,300 tons of wrought iron. And about 4,100 tones of cast iron were used for the dome of Capitol Hill in Washington D.C.
Along with their application in historic buildings, wrought iron and cast iron find a wide range of applications in everyday items and industrial elements.
Back in the day, for instance, wrought iron was frequently used for nails, nuts, bolts, rails, pipes, and even horseshoes.
Today wrought iron is prominently found in decorative interior and exterior pieces like doors, railings, gates, fences, pergolas, and more. Wrought iron is also common in patios and other outdoor furniture.
The use of cast iron depends on the type of cast iron. Gray cast iron is the most commonly utilized cast iron. It’s found in applications where high stiffness, vibration damping, high heat, and thermal conductivity are needed. That’s why the material is in high demand for the production of internal combustion engine cylinder boxes, gearboxes, disk brakes, rotors, and other automotive parts.
Gray cast iron is also a common cookware material with some of the most lasting and praised pots and pans made from this alloy.
The white cast iron is praised for its abrasion resistance and finds applications in elements like extrusion nozzles, cement mixers, crushers, pump impellers, pipe fittings, and flanges.
Malleable cast iron, thanks to its high tensile strength and flexibility, is used in electrical fittings and equipment, pipe fittings, hand tools, washers, farm equipment, and mining hardware.
Ductile cast iron is widely used in water piping and sewage installations, due to its superior ductility. It also finds applications in vehicle gears and suspension components, housings for wind turbines, and hydraulic parts.
Seeing the difference between the two iron alloys it’s clear that cast iron is more suitable for industrial applications with fewer home applications like piping or home kitchenware.
If you’re looking for those design pieces that will add to your home’s security and functionality at the same time, wrought iron will be a more fit choice. Wrought iron’s malleability is great for a range of interior and exterior projects from simple fireplace doors to sophisticated railing systems.
When it comes to home design and renovation we’re often faced with multiple options and choices. And choosing the best materials requires time in investigating what materials are best for your needs. This whole process can easily get overwhelming.
So to help you out we’ve gathered some fundamental information on what wrought iron and cast iron are; the differences between them; their best applications; the materials’ advantages and disadvantages.
For further consultation on the wide variety of design applications of wrought iron, you can get in touch with Cacciola Iron Works.
Anthony Cacciola’s team has been serving the New York and New Jersey area for almost 40 years, with multiple wrought iron projects adorning the homes of our repeat customers.
Get in touch today!