Ductile Iron Price per Pound: New Castings vs. Scrap 2025

The price of ductile (nodular) iron per pound varies according to whether you’re buying new castings, recycled scrap, or in bulk. As of early 2025, new ductile-iron raw castings from major foundries in China range from $0.64–$0.67 per pound (green‐sand process) and up to $0.75–$0.79 per pound for shell molding. In contrast, scrap‐grade ductile iron in the U.S. trades for about $0.06–$0.07 per pound. Bulk orders, process methods (green sand vs. resin sand vs. shell molding), and regional factors (labor, energy, logistics) can swing prices by ±15 %.

1. Definitions and Uses of Ductile Iron

Ductile iron, also called nodular or spheroidal-graphite iron, is produced by adding magnesium or cerium to molten iron, causing graphite to form as spheres (nodules) rather than flakes. These nodules impart high ductility, toughness, and fatigue resistance, making ductile iron ideal for pipes, gears, automotive parts, and heavy equipment components.

• Green-sand casting is the most common, cost-effective process for large volumes.

• Resin-sand and shell-molding yield smoother surfaces and tighter tolerances but at higher cost.

2. Current Market Prices for New Castings

Prices above are ex-works in Dandong, China (as of Dec 2024) and exclude machining, finishing, and shipping.

3. Scrap vs. New: Recycling Prices

Recycled ductile iron (castings, turnings, scrap) trades significantly lower than new castings. In North America:

• Cast-iron scrap (mixed gray and ductile): $0.06–$0.07 per pound

• Light iron (clean, no contaminant): ≈$0.03–$0.05 per pound

Scrap prices fluctuate daily based on local mill demand, global scrap exports, and seasonal factors.

4. Regional Variations

5. Cost Drivers and Manufacturing Overhead

1. Raw-material iron (scrap or pig iron): ~$0.15–$0.20 /lb

2. Alloying additions (Mg, Ce): +$0.02 /lb

3. Energy (fuel, electricity): +$0.10–$0.15 /lb

4. Labor & overhead: +$0.07–$0.10 /lb

5. Casting process premium: green-sand vs. shell (~$0.10 /lb difference)

Together, these add up to the $0.64–$0.79 range for finished new castings.

6. Bulk Ordering & Discounts

Larger orders also benefit from reduced per-unit shipping and handling.

7. Total Cost of Ownership & Lifecycle

While scrap is cheapest upfront, new ductile iron castings deliver superior mechanical properties and corrosion resistance, reducing lifecycle costs in critical applications (pipes, automotive, heavy machinery). Factoring in maintenance, downtime, and replacement over 25 years, new ductile iron often offers better total cost of ownership despite higher per-pound cost.

8. Industry Standards & Quality Impact

• ASTM A536 defines grades (60-40-18, 65-45-12, 80-55-06) that affect strength and ductility.

• Higher grades (80-55-06) require tighter controls and more expensive alloys, adding ~$0.05–$0.10 /lb.

• Conformance testing (tensile, elongation, hardness) adds overhead (~$0.01 /lb).

9. Tips for Cost Savings

1. Mix scrap and new: blend recycled metal into melt to lower alloy cost.

2. Optimize grade selection: use lower tensile grades when permissible.

3. Choose appropriate casting process: green-sand for large runs; shell for precision only where needed.

4. Negotiate long-term contracts: lock in prices and delivery.

5. Local sourcing: cuts shipping by $0.05–$0.10 /lb.

YouTube Video Recommendation

“Understanding Ductile Iron Casting Processes and Costs”

Six Common Questions

1. Why is new ductile iron so much more expensive than scrap?

New ductile iron castings incorporate quality controls, alloying, and energy-intensive processes that scrap does not. Scrap iron is simply raw material; using it requires melting, descaling, nodulizing, and finishing—each step adding cost. For example, magnesium addition for nodularity costs about $0.02–$0.03 per pound, and shell-molding adds $0.08–$0.10 per pound in labor and tooling. Quality testing (mechanical, chemical) contributes another $0.01 /lb, while energy (electric arc or cupola) runs $0.10–$0.15 /lb. All told, these steps transform $0.15 /lb scrap into $0.64–$0.79 /lb finished casting—a ~4× markup reflecting value addition and reliability.

2. How do global steel prices affect ductile iron pricing?

Ductile iron uses ~85–90 % ferrous input (scrap pig iron, steel turnings). When global steel billet prices rise, scrap-feed costs rise in tandem. A $50/ton increase in scrap market (≈$0.025 /lb) flows directly into the caster’s raw-material budget, typically passed through as a $0.02–$0.03 /lb surcharge. Energy and freight inflation compound this, so when international steel futures climb, ductile iron pricing tends to follow within 2–4 weeks.

3. How Do Different Casting Processes Influence the Price per Pound of Ductile Iron?

The choice of casting process—green-sand, resin-sand, or shell-molding—has a pronounced impact on the finished cost of ductile iron, typically ranging from $0.64 to $0.79 per pound for new castings. For example, green-sand casting, the most economical method, delivers a rough surface finish and slower cycle times, resulting in prices around $0.64–$0.67 per pound ex-works in leading Chinese foundries. In contrast, resin-sand casting—which uses synthetic binders for cleaner parts and faster mold handling—adds processing overhead, pushing costs to $0.71–$0.74 per pound. The highest-precision shell-molding process, prized for tight tolerances and minimal cleanup, commands up to $0.75–$0.79 per pound due to specialized tooling and thermal curing steps.

Energy consumption also varies: shell molds require pre-heating and longer cycle times, increasing electricity and fuel usage by 10–15 % compared to green-sand. Labor rates rise correspondingly—skilled technicians must maintain shell molds and oversee resin handling, adding $0.02–$0.04 per pound in overhead. Foundries recover these costs through per-pound surcharges embedded in their price schedules.

When comparing scrap: iron-foundry scrap (including mixed gray and ductile) in the U.S. trades near $100 per ton (≈$0.05 per pound) at yard prices, reflecting minimal processing. Recycled feedstock drastically undercuts new casting prices but requires re-melting, descaling, and nodulizing—steps that add back $0.15–$0.20 per pound in energy and alloying costs before the casting process even begins.

4. How Do ASTM A536 Grades Affect Ductile Iron Cost?

ASTM A536 defines four primary ductile iron grades—60-40-18, 65-45-12, 80-55-06, and 100-70-03—each with progressively higher tensile strength and tighter microstructural controls. These mechanical requirements translate directly into material and processing costs: the higher the grade, the greater the alloying, heat-treatment, and inspection overhead.

• Grade 60-40-18 (minimum 60 ksi tensile, 18 % elongation) is the baseline ductile iron grade and is often cast in green-sand at $0.73 per pound.

• Grade 65-45-12 raises tensile to 65 ksi and tightens inclusion control, typically produced in resin-sand for $0.64 per pound when quoting high volumes—reflecting a slight premium for binder costs and more extensive nondestructive testing.

• Grade 80-55-06, with an 80 ksi tensile requirement and minimal ductility trade-off, needs finer graphite nodule control and pearlite content, driving prices to $0.70 per pound in resin-sand or shell-mold processes.

• Grade 100-70-03 demands quenching and tempering or normalization steps, along with additional chemical analysis, adding $0.05–$0.10 per pound over Grade 80-55-06.

Higher grades also incur more rigorous inspection and certification costs—chemical spectrometry, tensile testing, impact testing (ISO 1083), and hardness checks—totaling $0.01–$0.02 per pound per batch. In practice, selecting a grade above what your application truly requires can inflate material spend by 10–20 %, so engineers should balance mechanical specifications against budget constraints.

5. Why Do Ductile Iron Prices Fluctuate Seasonally and with Market Cycles?

Ductile iron prices are sensitive to the broader metals cycle, exhibiting both seasonal and macro-economic swings. The primary drivers include iron ore futures, scrap availability, energy costs, and foundry capacity utilization.

Iron ore underpins ductile iron feedstock costs: Moody’s and other analysts forecast iron ore prices to hold between US$80 and $100 per tonne over the next 18 months, given softening demand and ample supply. A $10/tonne movement in ore spot prices translates to roughly $0.01 per pound swing in ductile iron raw-material cost.

Scrap metal availability dives in winter (construction slow-down), tightening supply and pushing yard prices above $110–$120 per tonne (≈$0.055–$0.06/lb) in Q4, while Q2 surges often see $90 per tonne (≈$0.045/lb) due to spring cleanup activities.

Energy costs—particularly natural gas for cupola furnaces—peak in summer months due to demand for residential cooling, raising energy surcharges by 15 %, which foundries typically recover at $0.02–$0.03 per pound.

Finally, foundry lead times lengthen during peak infrastructure seasons (spring–summer), with small orders delivered in 2–4 weeks, but bulk orders pushed to 6–8 weeks, adding inventory carrying costs that feed into per-pound quotations. Consequently, buyers often lock in Q4 pricing or negotiate long-term contracts to hedge against Q2–Q3 premiums.

6. What Are the 2025–2026 Price Outlook and Forecasts for Ductile Iron?

Market analysts project modest price stability for ductile iron into 2026, driven by offsetting trends in iron ore, energy, and scrap markets. Project Blue’s base case predicts iron ore tumbling below US$100 per tonne in late 2025, curbing raw-material cost pressure. However, if fiscal stimulus in China revives property development, ore could rebound to $120–$130 per tonne, adding $0.02–$0.03 per pound to ductile iron costs.

On the scrap front, rising electrification of scrap collection and export restrictions in key Asian markets may tighten U.S. scrap availability, nudging yard prices to $120–$130 per tonne (≈$0.06/lb) by mid-2025, up from $100 per tonne in early 2025.

Energy forecasts anticipate 5–10 % lower natural gas costs year-over-year in 2025–2026, potentially trimming cupola surcharges by $0.01–$0.02 per pound. Combined, these factors suggest finished new casting prices may range $0.88–$1.00 per pound by Q4 2025—up slightly from today’s $0.75–$0.79 but significantly cushioned by lower energy and foundry efficiencies.

Buyers should monitor the Producer Price Index for ductile iron castings (PPI 194.4 in Apr 2025) as an early indicator of foundry cost pass-throughs. Establishing flexible, index-linked contracts can help procurement teams manage this moderate upward trend without locking into outsized premiums.

References:

• ASTM A536 Standard Specification for Ductile Iron Castings — Official ASTM International standard defining grades and mechanical properties of ductile iron.
• Ductile Iron – Wikipedia — Comprehensive overview of ductile iron, including production methods and mechanical properties.
• U.S. Geological Survey (USGS) – Iron Ore Statistics and Information — Authoritative data on iron ore pricing and market trends affecting ductile iron raw materials.
• World Steel Association – Steel Price Monitor — Industry-leading source on scrap steel and raw material prices impacting ductile iron costs.
• ISO 1083: Cast irons — Classification — International standard for classification and testing of cast irons including ductile iron grades.