Lost Foam Casting Manufacturer
The reputation and leading lost foam iron casting foundry in East China — dedicated to small and medium-size ductile and gray iron castings with top quality. From raw casting to fully finished product, we perform all secondary machining and QC operations in-house.
Modern Foundry Area
Annual Casting Output
Automatic White Molding
2015 · NQA / UKAS
Modern production & testing equipment
Medium-frequency induction melting
Automatic white molding lines
Dry sand, no binder, no moisture
Certified through NQA (UKAS auditor)
Lost foam casting
Renyi Castings lost foam casting — a clustered model tree poured as one, producing accurate, near-net-shape iron parts
“Lost foam casting combines foamed-plastic models — shaped like the final casting — into a model cluster, which is coated with a refractory coating, dried, and vibrated into dry quartz sand. Molten metal is then poured in; the foam model vaporizes and the metal occupies its position, forming the desired casting after solidification and cooling.”
Also known domestically as “dry sand solid casting” and “negative-pressure casting,” lost foam needs neither parting lines, sand cores, nor mold closing and drawing — greatly simplifying the molding process while eliminating an entire class of casting defects.
Renyi Castings is second to none among lost foam casting foundries in East China, specializing in small and medium-size lost foam iron castings widely used in pneumatic component fittings, auto parts, and railway industry parts.
No Binder Sand
No Draft Angles
No Cores Needed
Near-Net Shape
Cast Aluminum
Ductile Iron
Large Parts Welcome
Gray Cast Iron
No Sand Core
GIFA 2019 Exhibitor
No Parting Line
Near-Net Shape
In-House Tooling
CNC Machining
In lost foam casting, foamed-plastic models are clustered, coated with refractory coating and dried, then buried in dry quartz sand and poured with liquid metal. Under high temperature the foam gasifies and cracks; the gas is discharged through the coating, and the molten metal takes the model’s exact position — forming a precise casting after solidification.
Dry-sand molding uses no binder, no moisture and no additives — the molding sand is completely recycled and reused, eliminating the sand-preparation and waste-sand-treatment departments altogether. Compared with traditional casting, lost foam offers unparalleled advantages in quality, cleanliness, and cost.
Lost foam casting removes the traditional bottlenecks of sand casting — cores, parting lines, mold drawing, and binders — to deliver cleaner, more accurate, lower-cost iron castings.
The casting dimension is accurate and consistent from piece to piece, ideal for parts requiring tight repeatability across a production run.
Castings come out with a smooth surface finish straight from the mold, reducing downstream grinding and finishing work.
No sand-core parts are needed, totally improving casting quality — sand casting carries defect risk during core making and core setting.
Neither mold closing nor pattern drawing is required, greatly simplifying molding and eliminating defects and scrap caused by mold drawing and boxing.
Dry-sand molding uses no binder, no moisture and no additives — eradicating the defects and scrap caused by moisture, additives and binders.
The sand system is greatly simplified; molding sand is completely recycled and reused, removing both sand-preparation and waste-sand departments.
Falling sand is extremely easy, greatly reducing the workload and labor intensity of the shakeout (sand-falling) operation.
Stable casting weight and reduced machining allowance lower raw casting weight and cost compared with traditional sand casting.
A continuous, controlled workflow — from foam model injection to finished, machined component. Each stage below is photographed on our own production floor.
Lost foam unlocks shapes and cost structures that conventional sand casting and investment casting cannot match — especially at large part sizes.
No parting line, no draft angle, no core box. Complex internal passages, undercuts, and large hollow sections are cast in a single pour. Part complexity is limited by foam pattern design — not by mold assembly constraints.
From multi-ton mold frames for automotive lightweight components to crusher frames and large industrial housings — lost foam scales to sizes where investment casting is impractical and sand casting struggles with dimensional control.
Compared to investment (lost wax) casting, lost foam requires no ceramic shell building, no wax injection tooling, and no autoclave dewaxing. For large and medium parts, this translates to significantly lower per-unit and tooling costs.
Tight dimensional tolerances reduce machining stock and post-processing requirements. Smooth as-cast surfaces minimize secondary operations — resulting in shorter lead times and lower total cost of ownership for the buyer.
Renyi specializes in lost foam ductile iron and gray cast iron castings across the most widely specified international grades.
The ductile iron specifications we mainly cast
GGG40
GGG50
GGG60
AISI/ASTM 60-40-18
65-45-12
EN-GJS-400-18
EN-GJS-400-15
EN-GJS-500-7
EN-GJS-450-10
EN-GJS-600-3
The gray cast iron specifications we mainly cast
GG15
GG20
GG25
ASTM A48
GG30
CLASS 30A
CLASS 35A
CLASS 40A
CLASS 45A
EN-GJL-150
EN-GJL-200
EN-GJL-250
EN-GJL-300
A cross-reference of gray iron and ductile (SG / nodular graphite) iron grades across ISO, GB, ASTM, DIN, EN, JIS, UNI, NF, BS, IS, UNF, NBN, AS, SS and NS standards.
| Country | Standard | Equivalent Grades of Gray Iron (Grey Cast Iron) | ||||||
|---|---|---|---|---|---|---|---|---|
| Class 1 | Class 2 | Class 3 | Class 4 | Class 5 | Class 6 | Class 7 | ||
| ISO | ISO 185 | 100 | 150 | 200 | 250 | 300 | 350 | — |
| China | GB 9439 | HT100 | HT150 | HT200 | HT250 | HT300 | HT350 | — |
| USA | ASTM A48 | — | NO.20 / NO.25 | NO.30 | NO.35 | NO.40 / NO.45 | NO.50 | NO.55 / NO.60 |
| Germany / Austria | DIN 1691 | GG10 | GG15 | GG20 | GG25 | GG30 | GG35 | GG40 |
| European | EN 1561 | EN-GJL-100 | EN-GJL-150 | EN-GJL-200 | EN-GJL-250 | EN-GJL-300 | EN-GJL-350 | — |
| Japan | JIS G5501 | FC100 | FC150 | FC200 | FC250 | FC300 | FC350 | — |
| Italy | UNI 5007 | G10 | G15 | G20 | G25 | G30 | G35 | — |
| France | NF A32-101 | — | FGL150 | FGL200 | FGL250 | FGL300 | FGL350 | FGL400 |
| UK | BS 1452 | 100 | 150 | 200 | 250 | 300 | 350 | — |
| India | IS 210 | — | FG150 | FG200 | FG260 | FG300 | FG350 | FG400 |
| Spain | UNF | — | FG15 | FG20 | FG25 | FG30 | FG35 | — |
| Belgium | NBN 830-01 | FGG10 | FGG15 | FGG20 | FGG25 | FGG30 | FGG35 | FGG40 |
| Australia | AS 1830 | — | T150 | T220 | T260 | T300 | T350 | T400 |
| Sweden | SS 14 01 | O110 | O115 | O120 | O125 | O130 | O135 | O140 |
| Norway | NS11 100 | SJG100 | SJG150 | SJG200 | SJG250 | SJG300 | SJG350 | — |
| Country | Standard | Equivalent Grades of Ductile Iron (SG Iron, Nodular Graphite Iron) | ||||||
|---|---|---|---|---|---|---|---|---|
| Grade 1 | Grade 2 | Grade 3 | Grade 4 | Grade 5 | Grade 6 | Grade 7 | ||
| ISO | ISO 1083 | 400-15 / 400-18 | 450-10 | 500-7 | 600-3 | 700-2 | 800-2 | 900-2 |
| China | GB 1348 | QT400-18 | QT450-10 | QT500-7 | QT600-3 | QT700-2 | QT800-2 | QT900-2 |
| USA | ASTM A536 | 60-40-18 | 60-42-10 / 65-45-12 | 70-50-05 | 80-55-06 / 80-60-03 | 100-70-03 | 120-90-02 | — |
| Germany / Austria | DIN 1693 | GGG40 | — | GGG50 | GGG60 | GGG70 | GGG80 | — |
| European | EN 1563 | EN-GJS-400-15 / 400-18 | EN-GJS-450-10 | EN-GJS-500-7 | EN-GJS-600-3 | EN-GJS-700-2 | EN-GJS-800-2 | EN-GJS-900-2 |
| Japan | JIS G5502 | FCD400 | FCD450 | FCD500 | FCD600 | FCD700 | FCD800 | — |
| Italy | UNI 4544 | GS370-17 | GS400-12 | GS500-7 | GS600-2 | GS700-2 | GS800-2 | — |
| France | NF A32-201 | FGS370-17 | FGS400-12 | FGS500-7 | FGS600-2 | FGS700-2 | FGS800-2 | — |
| UK | BS 2789 | 400/17 | 420/12 | 500/7 | 600/7 | 700/2 | 800/2 | 900/2 |
| India | IS 1865 | SG370/17 | SG400/12 | SG500/7 | SG600/3 | SG700/2 | SG800/2 | — |
| Spain | UNF | FGE38-17 | FGE42-12 | FGE50-7 | FGE60-2 | FGE70-2 | FGE80-2 | — |
| Belgium | NBN 830-02 | FNG38-17 | FNG42-12 | FNG50-7 | FNG60-2 | FNG70-2 | FNG80-2 | — |
| Australia | AS 1831 | 300-17 / 400-12 | — | 500-7 | 600-3 | 700-2 | 800-2 | — |
| Sweden | SS 14 07 | 0717-02 | — | 0727-02 | 0732-03 | 0737-01 | 0864-03 | — |
| Norway | NS11 301 | SJK-400.3 / SJK-400 | — | SJK-500 | SJK-600 | SJK-700 | SJK-800 | — |
Comparison table for gray iron and ductile iron grades of various standards, compiled by Renyi Castings foundry — covering ISO, GB, ASTM, DIN, EN, JIS, UNI, NF, BS, IS, UNF, NBN, AS, SS and NS.
From QC inspectors to every operator on the floor, we treat quality as the first priority — holding the same high standard from first-article sample through mass production.
“Quality is life.”
During first-article sampling and production, our team maintains quality at the same high level. We are confident in our products — and our customers are happy with the quality they receive in every mass-production shipment. That mutual trust is why customers keep releasing repeat orders and new projects.
Maintaining the highest standards of excellence in products, quality and customer service is our company’s founding principle.
Our own engineering team designs the lost foam casting tooling, and our internal tooling workshop machines and assembles the molds. This helps clients improve casting quality, shorten first-article approval time, and save tooling cost.
Full elemental chemical composition verification of every melt.
Graphite morphology, nodularity and matrix structure analysis.
Non-destructive detection of internal shrinkage and porosity.
Rapid C / Si check on molten iron before pouring.
Tensile, yield and elongation testing on cast test bars.
Brinell hardness verification to grade specification.
Critical-dimension measurement against drawing tolerance.
Certified through NQA, a UKAS-recognized auditor.
Our lost foam iron castings are widely used wherever accurate, clean, near-net-shape iron components are required.
Valve bodies, cylinder caps and connector fittings cast to accurate, repeatable dimensions with smooth surfaces.
Brackets, housings and structural iron components for automotive applications, machined and finished in-house.
Heavy-duty ductile and gray iron castings meeting the durability and consistency demands of rail components.
Lost foam is best suited for parts weighing 0.5 kg to several tons. It excels at medium-to-large complex parts where sand casting cannot achieve the required internal geometry and investment casting is cost-prohibitive due to part size. Very small, highly precise parts are better served by investment (lost wax) casting.
Yes. We regularly produce both cast aluminum alloys (AlSi9Mg, A356, A380) and ductile / gray iron (QT series, HT series) using the lost foam process. Both material families can be produced from the same foam pattern tooling — ideal for customers evaluating material options before final specification.
Sample (first article) lead time: 15 working days from approved drawings and foam pattern. Production order lead time: 30 days. For urgent projects, expedited timelines can be discussed. RFQ feedback is returned within 12 hours; full quotation within 48 hours.
Lost foam is primarily used for cast iron and aluminum — these are the materials where the process delivers the best technical and cost results. For carbon steel, stainless steel, and high-alloy steels requiring tight tolerances, we recommend ourInvestment Castingprocess instead, which handles a broader range of ferrous and non-ferrous alloys.
Renyi Castings is certified to ISO 9001 and IATF 16949. All shipments are accompanied by dimensional inspection reports and material test certificates. NDT options (UT, MT, PT, X-ray) are available upon request. We supply to automotive-tier and industrial OEM buyers who audit our quality system directly.
Send your 2D / 3D drawings, material grade, required weight range, and target annual volume. Our engineering team will assess process suitability and return a full quotation — including DFM notes on foam pattern design — within 12–48 hours.
Process recommendation — lost foam vs. sand vs. investment
DFM review on foam pattern design & gating
Tooling cost + unit price quoted separately
Machining, heat treatment & surface treatment options
NDT & material certification options included
Send drawings (STEP / DXF / PDF) to RFQ@renyicastings.com — response within 12 hours. Sample delivery in 15 days.