Grey Iron Castings
High compressive strength. Natural vibration damping. Cost-effective at scale. As a specialized grey iron foundry, Kurt Foundry supplies custom, fully machined castings to industrial buyers across North America, Europe, and Southeast Asia.
Request a Free QuoteOur Grey Iron Sand Casting Process
Consistent quality starts with precise metallurgical control and proven mold engineering for large industrial components.
CAD & Pattern Making
We review your CAD files for castability and build the tooling and pattern, designing gating and risering systems to produce dense, defect-free iron on every pour.
Sand Mold Making
Using high-grade resin sand, we produce rigid molds that hold tight dimensional tolerances and a consistent surface finish across the run.
Iron Melting
Scrap steel and pig iron are melted in medium-frequency induction furnaces under tightly controlled temperature and charge composition.
Carbon Equivalent Testing
Molten iron is sampled and tested by spectrometer before pouring to confirm Carbon Equivalent (CE) falls within the target range for the specified grade.
Cooling
Castings cool under controlled conditions inside the mold before shakeout, allowing the microstructure to fully solidify without internal stress.
CNC Machining
Castings are shot-blasted and fully CNC machined in-house — drilling, milling, boring, and turning to final print dimensions.
Sampling Inspection
Batch samples undergo spectrometric analysis and mechanical testing to confirm every part meets the target ASTM or DIN grade specification.
Packing & Shipping
Parts are cleaned, rust-proofed, and export-packed to withstand ocean freight, then shipped worldwide via DDP or FOB logistics.
Have a Drawing Ready? Talk to Kurt Foundry.
Send your 2D or 3D file — a foundry engineer will confirm castability and return a firm quote for our grey iron casting service within 48 hours.
Submit Your InquiryGrey Iron: The Lowest-Cost Casting Material for the Job
Grey iron is the cheapest ferrous casting material available — low melt cost, no expensive alloying, and fast machining keep per-part price down. It’s the default choice for buyers who need a custom grey iron casting service without paying for the tensile strength of steel or ductile iron.
Our foundry casts personalized grey iron parts from 50 lbs to 5,000 lbs, fully CNC machined and CMM-inspected in-house, and ships on DDP or FOB terms with full material certifications.
Common Grey Iron Casting Grades
Our metallurgy team controls carbon and silicon equivalents to produce the correct flake structure for each bespoke grade, whether the specification is written to ASTM/SAE (gray iron) or ISO/EN (grey iron).
| Standard / Grade | Min. Tensile Strength (MPa) | Typical Hardness (HB) | Common Applications |
|---|---|---|---|
| ASTM A48 Class 20 / 25 | ≥ 150 | 140 – 190 | Counterweights, non-pressure housings, hand wheels, light-duty covers. |
| ASTM A48 Class 30 | ≥ 207 | 170 – 220 | Flywheels, pump casings, gearboxes, machinery bases. |
| ASTM A48 Class 35 | ≥ 241 | 190 – 240 | Heavy machine tool beds, hydraulic cylinders, brake rotors. |
| ASTM A48 Class 40 | ≥ 276 | 200 – 260 | High-stress diesel engine blocks, heavy-duty flywheels. |
| DIN EN 1561 EN-GJL-250 | ≥ 250 | 180 – 230 | European equivalent for general engineering and machine parts, specified as grey iron under EN 1561. |
What Does a Grey Iron Casting Cost?
Grey iron is the most affordable ferrous casting material we offer, typically running $1–$10 per kg depending on grade, finishing, and order volume. Use the ranges below as a starting point — your exact quote will depend on the drawing.
As-Cast / Minimal Finishing
Shot-blasted and dimensionally inspected, delivered as a raw or lightly finished casting for your own downstream machining.
Fully CNC Machined
Complete CNC machining, drilling, and tapping — ready for immediate assembly on arrival.
Larger order volumes reduce the per-kg price. The final quote depends on part geometry, tolerance requirements, and machining scope.
What We Cast in Grey Iron
Grey iron is the standard material choice where mass, damping, and machinability matter more than tensile strength. Below are the made-to-order components our foundry produces most frequently as part of our grey iron casting service.
Heavy Counterweights
Grey iron’s high density and low cost per kilogram make it the standard choice for elevator, crane, tractor, and construction equipment counterweights. We cast single, personalized pieces up to 5,000 lbs.
Industrial Flywheels
Cast to your bespoke dimensional drawings with tight bore and face tolerances. Grey iron’s vibration damping properties make it well-suited for flywheels in heavy-duty power transmission and press applications.
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Custom Hand Wheels
Cast iron hand wheels offer structural rigidity and a solid grip for valve actuation and heavy machinery adjustment. We cast standard and fully custom, made-to-order profiles to your drawings.
See Your Part Cast by Kurt Foundry
Not sure which grade fits your application? Send your drawing and duty cycle — we’ll recommend the right spec.
Submit Your InquiryWhat Our Clients Say
Grey iron castings shipped from Kurt Foundry to buyers across six continents.
Precise dimensions and excellent grey iron casting quality!
Perfect surface finish and extremely fast shipping. Highly recommended!
Outstanding vibration damping properties. Highly recommend Kurt Foundry.
The grey iron casting structure is dense and entirely flawless.
One Supplier. Casting to Finished Part.
Kurt Foundry runs dedicated heavy casting lines for custom grey iron castings at our Shandong-based foundry. From pattern making through CNC machining and final inspection, all production steps are handled in-house.
Buyers receive material test reports, spectrometry data, and CMM dimensional reports with each shipment. No third-party lab delays.
We ship on DDP or FOB terms to buyers in North America, Europe, Southeast Asia, and the Middle East. Lead time and freight options are confirmed at the quotation stage.
- Heavy Section Capacity: 50 lbs – 5,000 lbs per Piece
- In-House 5-Axis CNC Machining & CMM Inspection
- Pre-Pour Spectrometry & Carbon Equivalent Verification
- DDP / FOB Shipping to North America, Europe & Beyond
- Material Certs & Inspection Reports with Every Order
Grey Iron Casting FAQs
Our foundry is based in Weifang City, Shandong Province, China — one of the country’s established centers for iron and steel casting. Casting, machining, and inspection all happen at this single site.
We ship worldwide on DDP or FOB terms directly from our foundry, with export packing rated for ocean freight.
Yes — no metallurgical difference. “Grey iron” is the spelling used in ISO 185, EN 1561, and most markets outside North America. “Gray iron” is the ASTM and SAE spelling used in the United States and Canada.
Kurt Foundry casts to both naming systems. Send us either an EN-GJL grade or an ASTM class and we will match the equivalent specification.
Grey iron is the better choice when vibration damping, thermal conductivity, and cost per kilogram are the primary concerns — machine bases, counterweights, motor housings, and pump casings are common examples.
Ductile iron is the correct choice when the part must withstand impact loading or bending stress, or when elongation at break is a design requirement. If you are uncertain which material fits your application, send us the drawing and we will advise.
The graphite flakes embedded in the iron matrix act as a natural chip breaker and cutting lubricant during CNC operations.
The result is faster cutting speeds, lower tool wear, and cleaner surface finishes compared to carbon steel or ductile iron — which reduces machining cost and cycle time on complex components.
Our heavy resin sand casting lines handle single grey iron components from 50 lbs up to 5,000 lbs (approximately 2.5 metric tons) per piece.
For parts outside that range, contact us directly. We can advise on design modifications or split-casting approaches where applicable.
Welding grey iron is technically possible but carries significant risk of cracking during the heating and cooling cycle due to the material’s high carbon content and low ductility.
Where possible, we recommend redesigning assemblies so components are bolted together or cast as a single piece. Our DFM review will flag any weld-dependent designs before tooling is cut.
Yes. Kurt Foundry provides fully integrated production — casting, CNC machining, and inspection under one roof.
Parts are delivered ready for assembly. Buyers specify the machining scope in the RFQ, and we quote casting and machining together as a single turnkey price.
Ready to Quote Your Grey Iron Project with Kurt Foundry?
Submit 2D drawings or 3D CAD files. A foundry engineer will review castability, confirm the appropriate ASTM or EN grade, and return a detailed quote — including machining scope and DDP/FOB pricing — within 48 hours.
Send Your RFQ Now