At the heart of every radiator we produce is a time-tested material: cast iron. But what exactly is cast iron, and why has it been used for centuries — including in the radiators we build today?
Let’s take a closer look at the properties, history, and craftsmanship behind cast iron and how we use it to create beautiful, durable radiators built to last for generations.
What is Cast Iron?
Cast iron is a strong iron-based alloy that’s melted down and poured into moulds to form solid shapes — like radiators. It’s usually made from a material called pig iron, which is rich in carbon.
There are two common types:
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White cast iron, which is hard and brittle, allowing cracks to travel straight through it.
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Grey cast iron, which contains graphite flakes. These flakes help stop cracks from spreading, making it much more durable — and ideal for radiators.
Our radiators are made from high-quality grey cast iron to ensure both strength and reliability.
What’s in the Alloy?
The primary elements in cast iron are:
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Carbon (2.1%–4%)
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Silicon (1%–3%)
This chemical makeup lowers the melting point of the iron, making it easier to pour into intricate moulds. It also gives the iron excellent fluidity, castability, wear resistance, and machinability — all crucial for producing detailed, high-performance radiators.
A Brief History of Cast Iron
Cast iron has been around for over 2,000 years, first used in China for weapons, tools, and architecture. By the 15th century, it was adopted in Europe for artillery and structural use. In the 1770s, The Iron Bridge in Shropshire became the first bridge made entirely from cast iron.
During the Victorian era, cast iron became the go-to material for radiator manufacturing — thanks to advances in mould-making and the ability to control graphite content for strength and appearance.
Precision Casting Today
Modern technology, including spectroscopy, allows us to precisely control the graphite content in our cast iron — the key to getting it just right:
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Too much graphite: the iron becomes too tough and difficult to machine (such as threading).
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Too little graphite: the metal becomes brittle and fragile.
We’ve spent years perfecting the balance to ensure our cast iron is strong, stable, and ideal for central heating systems.
Built to Last — With a Guarantee
Our cast iron radiators are developed in partnership with industry-leading casting experts and come with guarantees of up to 25 years. Every radiator we make is assembled, tested, and finished in our Yorkshire workshop to the highest standards.
When you choose one of our radiators, you're investing in a piece of functional craftsmanship that combines engineering, history, and timeless design.
Need help choosing the right radiator?
Call us on 01723 321 333 or email info@periodstyle.co.uk — we’re happy to help.
