Why does cast iron pay differently than regular steel scrap of the same weight?
Short answer: Cast iron and steel are chemically different ferrous alloys with different melting characteristics and end uses, so they're graded and priced as separate categories rather than interchangeably — cast iron commonly prices below clean steel scrap because of its higher carbon content and the way it's processed differently in foundries versus steel mills.
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List Free →The chemical difference that drives grading
Cast iron has a significantly higher carbon content than most steel, which changes how it melts and what it can be remelted into — foundries that specifically process cast iron are a different market from steel mills, and that market distinction is reflected in a separate, typically lower, price point.
How to tell if you have cast iron or steel
Cast iron is generally more brittle, with a duller, grainier surface if broken or chipped, and is common in older plumbing fittings, engine blocks, and machine bases. Steel is more ductile and typically has a brighter fracture appearance — a buyer can usually confirm quickly if you’re unsure.
Is it worth separating cast iron from steel yourself
For any meaningful volume, yes — mixing cast iron into a steel load risks the entire load being priced down as mixed ferrous, while keeping them separate lets each material get its correct, higher blended value across the two categories.
How ScrapTrade Makes This Easier
Listing cast iron items separately from steel scrap on ScrapTrade — engine blocks, old pipe fittings, machine bases — helps foundry-focused buyers find exactly what they’re sourcing.
Ready to sell or source steel and ferrous scrap without the guesswork? ScrapTrade connects verified buyers and sellers with escrow-protected payments and transparent weighing.
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