At 2025 scrap prices the charge metal in a gray iron green sand casting works out to about $0.49 per kilogram of good casting shipped, $0.22 per pound. Everything above that — molding, cores, cleaning, machining, tooling and overhead — is quoted per piece, not per kilogram.
Green sand sits at the bottom of the sand-process price ladder.
How Much Does a Green Sand Casting Cost per Kilogram
The layer of the price that can be stated per kilogram with authority is the metal charge, and for ferrous alloys it runs from about $0.49 per kilogram of good casting for gray iron to about $4.13 for 18/8 stainless. Every ferrous charge starts from the same base, the ferrous scrap composite price, $319 per metric ton in 2025.
| Alloy | Charge metal, $/kg melted | Casting yield used | Metal in a shipped casting, $/kg ($/lb) |
|---|---|---|---|
| Gray iron | $0.319 | 65% | $0.49 ($0.22) |
| Ductile iron | $0.319 plus magnesium treatment | 65% | $0.49 plus treatment |
| Carbon steel | $0.319 | 55%, or 45% on job-shop work | $0.58 ($0.26) / $0.71 ($0.32) |
| Stainless, 18/8 type | $2.27 | 55% | $4.13 ($1.87) |
Every figure in that table is metal only, per kilogram of good casting shipped, before melting energy, molding, cleaning, machining, heat treatment, packing and freight.
Above the metal layer, a price per kilogram stops being a price. AFS is blunt about it in its guidance to casting buyers: a cost per pound cannot be fairly compared between castings ordered in different quantities or needing different man-hours.
Castings from a few ounces to 500 lb are routine green sand work, and the process is rated to about a ton. Heavier or more complex short-run parts normally come back quoted as no-bake.
What Drives the Cost of a Green Sand Casting
Five lines make up the price — metal, tooling, molding and cores, cleaning and machining, and the tolerance and finish called out on the drawing — and which one is largest depends on how many parts you order more than on how much the part weighs.
A published cost model run on a sand-cast radial pump, projected to a 5,000-part order, allocates about 50% of the cost to material and 30% to tooling, with labor near 1%. For the ten-piece order the authors actually costed, labor was the largest driver and material fell behind it.
Of these five, the tolerance and finish on the drawing are the cost you control most directly, because you write the drawing.
Metal and Pour Yield
The metal line is the alloy’s charge price multiplied by the weight poured, and the weight poured is the part weight divided by the casting yield.
Metal cost per part = alloy charge price per kg × (part weight ÷ casting yield)
Yield is the weight that ships as usable casting against the weight poured, gating and risers included. Green sand iron work runs around 60%, sand casting generally 50–65%, and steel lower: 55% in industry accounting and 45% for job-shop steel outside railroad and investment work.
On the metal line alone, gray iron and ductile iron are the cheapest ferrous castings to pour. Carbon steel is about 1.2 times gray iron at 55% yield and 1.4 times at job-shop yields, while stainless of the 18/8 type is roughly eight times either iron.
Pattern and Order Volume
The pattern is a one-time cost, and its cost per part depends on how many castings it produces before it is retired.
Tooling cost per part = pattern cost ÷ castings poured from that pattern
Foundries choose the pattern material from your annual volume.
| Pattern material | Annual volume it is chosen for | What comes with it |
|---|---|---|
| Wood | About 50 pieces a year or fewer | Cheapest to build; wears quickly, absorbs moisture and swells, so dimensions drift |
| Plastic or polyurethane | Up to 5,000 pieces a year | Direct replacement for wood, more moisture- and heat-resistant |
| Aluminum or iron | Over 5,000 pieces a year | Costliest to build and to revise; best dimensional stability, and what automated matchplate and cope-and-drag lines run |
A fixed block of work repeats on every order, and a release against a blanket order counts as a separate order at the foundry. A year’s volume taken in four releases is priced as four setups.
Your volume also has to fit the plant you send it to: a low-volume part sourced at a high-volume facility costs more than it should. A pattern run past its useful life is a false saving — off-dimension castings raise machining and finishing cost on every piece that follows.
Molding and Cores
Making the mold is the cheapest line on a green sand quote. The molding cost per part is set by how many parts fit in one mold, and mold size drives this more than part weight does.
Cores are a different sand system and a dearer one, and they are the place to look before complexity in general. Shape that the mold can simply carry costs nothing extra, while every internal passage has to be cored. Holes below about 0.19 in. cannot be cast at all, and small holes are often cheaper drilled than cored.
Cleaning and Machining
Cleaning and machining are the lines your drawing sets, and they are billed in labor minutes. At an $85 hourly rate a minute of grinding costs $1.42, so every ground surface on the print has a price.
Three items on most drawings are worth a second look before the RFQ goes out:
- Parting line: ground flush with the surrounding surface, or acceptable as-cast?
- Riser and ingate contacts: ground smooth but left as a raised pad, or removed completely?
- Shot blast after grinding: needed, or carried forward from an older drawing?
Machining is the larger of the two lines. The right machining allowance is not one number — large or low-volume castings carry more than small, high-volume ones — and the count of machined faces matters as much as the stock on each.
Tolerance and Wall Thickness
A tighter tolerance or a finer as-cast surface is paid for in rejects, and the most expensive thing you can put on a green sand drawing is a cosmetic requirement: demanding visually defect-free surfaces raises the scrap rate and can easily add 15% or more to the casting. Check the dimension against the tolerance band green sand already holds as-cast before you tighten it.
Wall thickness behaves the same way from both ends. Conventional steel casting practice suggests 0.25 in. (6 mm) as a minimum section, and a wide variation in section thickness raises the scrap rate on its own. Heavy sections cost money at the other end, since the foundry has to feed them with extra risers, chills or padding.
Why Green Sand Is the Cheapest Sand Casting Process
Green sand is cheapest because the mold is made of material the plant already owns. The sand is reclaimed and reused many times over, and only the fraction that has degraded gets replaced; a chemically bonded mold consumes 1–3% fresh binder every time one is made.
Rate is the second reason. A modern vertically-parted flaskless line runs up to about 500 molds an hour.
Cheap tooling is not one of the reasons. No-bake molds are not compacted hard, so wood and plastic patterns serve there too, and AFS rates no-bake tooling as low in cost as that of any production casting process.
An unfinished no-bake casting typically costs more than the same part in green sand, and no-bake earns the difference back in machining: tighter tolerances and less dimensional variation mean less stock to remove. No-bake takes over on run size and part size, suiting runs of 1–5,000 castings a year and parts from 1 lb to 50,000 lb, well past what green sand handles.
Shell molding is another chemically bonded system, and the same cost logic applies. Where the tolerance requirement outruns any sand mold, the comparison moves to investment casting.
What the Ex-Works Price Leaves Out
The ex-works price leaves out everything between the foundry gate and a part your line can run: heat treatment, paint or coating, packing, inland freight, ocean freight, duty, inspection and certification, and the cost of the money tied up while the parts are in transit.
For a US buyer importing, duty is the largest of those lines and the most commonly forgotten. Cast iron and cast steel articles under HTS heading 7325 sit on the Section 232 derivative-steel lists: as of September 2026 they carry an additional 25% or 50% of full customs value depending on the statistical suffix of the code, with no free-trade-agreement waiver and no drawback.
Check the current rate in CBP’s Section 232 guidance before you price anything.
The Drewry World Container Index stood at $4,500 per 40 ft container in mid-September 2026, with Shanghai to Los Angeles at $7,712. Divide it by the number of castings in the container to get the figure that belongs in your piece price.
Cash tied up in a container and in safety stock costs you your own borrowing rate — bank prime was 7.00% on September 17, 2026 — across every week the parts are neither at the foundry nor on your line.
Several of these operations can be bought from the foundry, often more cheaply than elsewhere: heat treatment, paint and coating, and the higher levels of inspection and testing are routine work in a casting plant. That also means two quotes are not comparable when one foundry carries them and the other stops at the raw casting.
A complete inquiry keeps these lines inside the quote. State on the RFQ:
- Casting drawing: dimensional tolerances, which surfaces are machined, and datum points for locating.
- Material specification and grade: written as the standard writes it, for example ASTM A27 Grade 60-30 Class I.
- Supplementary requirements: the test method and the acceptance criteria together, such as radiographic examination to ASTM E94 accepted at ASTM E186 severity level 2.
- Run length and releases: the annual quantity and how many separate releases it will be taken in.
- Inspection level: which tests, on what proportion of pieces, and how often — hardness, magnetic particle, radiography, pressure testing.
- Packaging and incoterm: containers and rust protection, and which party carries freight, insurance, customs formalities and any pre-shipment inspection.