How does the brittleness of cast iron limit its use in foldable outdoor chairs?

Cast iron, while known for its strength and durability, has a significant drawback—brittleness—that makes it unsuitable for foldable outdoor chairs. Unlike more flexible materials like aluminum or steel, cast iron is prone to cracking or breaking under stress, particularly at hinge points where folding mechanisms require repeated movement. This brittleness arises from its high carbon content, which reduces tensile strength and impact resistance.

Foldable chairs demand materials that can withstand frequent bending and weight shifts without failing. Cast iron’s lack of elasticity means it cannot absorb shocks or adapt to dynamic loads, increasing the risk of sudden fractures. Additionally, outdoor conditions—such as temperature fluctuations and moisture—exacerbate its brittleness, leading to corrosion-induced weakening.

For these reasons, manufacturers opt for ductile metals or composites in foldable designs, prioritizing safety and longevity over cast iron’s aesthetic appeal. While cast iron excels in static applications like bench frames, its brittleness disqualifies it from practical use in foldable outdoor chairs.