The Material Difference: Cast Steel Over Cast Iron

“When iron contains in its composition over 2% of carbon it becomes known as cast iron, a metal which melts at a comparatively low temperature and is capable of being cast with very sharp lines. It is used a great deal for finishing work, though from its brittle nature and lack of tensile strength it is not utilized to any great extent for constructive purpose.“

Blackall, C. Howard. (1890). Builder’s hardware: a manual for architects, builders and house furnishers. Boston: Ticknor and Company.

The above excerpt from the 1890 edition of “Builder’s Hardware” explains why Cast Iron has been widely regarded as a poor material choice for functional hardware. Cast iron hardware has broken or rusted away on many beautiful, historic homes throughout the US because it is brittle and prone to corrosion.

At Lynn Cove Foundry & Forge the improvements in modern steel making allow us to use cast steel instead of cast iron. We are are now making gravity-locking shutter hinges in cast steel. The precision of the steel casting process is even better than cast iron, and the tensile strength and ductility of steel means they hold more weight, will not fracture, and are corrosion resistant.

Neat fact: The stainless steel and galvanized steel castings look just alike, but a magnet will reveal the material difference – it won’t stick to the stainless steel casting. That’s due to the chromium content. The corrosion resistant properties of chromium in the alloy is why stainless is specified for coastal building projects. It comes at a premium over mild steel, however, so we have made both materials available to suite the building environment as needed. We recommend structures within 25 miles of salt water stick to stainless steel over mild steel when selecting their materials.

Learn more here: Louisiana Style Gravity-Locking Shutter Hinges