Non-deformable, robust, and durable
The key difference compared to steel lies in its high carbon content (over two percent), which means cast iron cannot be forged or shaped – it can only be cast. It expands and contracts less than steel, has significantly lower scaling (only at around 800 degrees), and offers much more precise fits. Cast iron is mainly used for components that need to be especially robust and long-lasting.
Interchangeability of individual parts
In earlier times, casting small parts was the only economical way to produce uniform components. Sheet steel almost always requires mechanical processing. Steel fireplaces only became suitable for series production and affordable through CNC machines, but in terms of quality, they cannot be compared to those made of cast iron. Since the individual parts are bolted together with sealing surfaces, cast iron components can now also be easily replaced when needed.
Resistant even under extreme heat
In low-cost appliances made of sheet steel, very thin steel is often used to save material costs. However, this carries the risk that the appliance may warp, bulge, develop cracked welds, or have doors that no longer close properly after extended use. High-quality steel appliances have a smooth surface and finely ground welds. While steel units can be damaged by improper heating, cast iron is virtually indestructible.
Conclusion
As a general guideline: for systems designed primarily to generate heat rather than atmosphere, cast iron is the better choice – for example, in tiled and storage stoves. In contrast, fireplaces with large glass panels are typically made of steel.
Expert advice
It’s important to note that cast iron takes longer to heat up, but it also releases warmth for a longer period of time. With a steel fireplace, it’s the other way around. It heats up quickly – but also cools down faster once it’s turned off. Which material suits you better depends entirely on your personal needs.
