Gravity Casting Built for Strength & Density
We pour molten aluminum into reusable steel molds using nothing but gravity — producing dense, low‑porosity parts that are heat‑treatable and pressure‑tight. IATF 16949:2016 certified, with production in Thailand and quality managed from Canada.
What Is Gravity Casting?
Gravity casting (also called permanent‑mold casting) is a way to make metal parts by pouring molten metal into a reusable steel die using nothing but gravity — no high‑pressure injection needed. The metal fills the mold slowly and solidifies against a chilled steel wall, which produces denser, stronger parts with far less internal porosity than high‑pressure die casting.
That matters because low porosity means your parts can be T6 heat‑treated for extra strength and are naturally pressure‑tight — no leaking under hydraulic or pneumatic loads. It works best with aluminum, zinc, and copper alloys, and it's the go‑to choice for medium‑volume production (roughly 500–50,000 parts per year). Meco handles gravity casting as part of our full manufacturing service, so your parts can go straight from casting to CNC machining, finishing, and assembly — without switching suppliers.
Why Choose Gravity Casting for Your Parts?
If you need strong, dense, heat‑treatable metal parts at medium volume, gravity casting is hard to beat. It's the go‑to process for automotive, aerospace, and heavy equipment manufacturers who want leak‑proof performance without the tooling cost of high‑pressure die casting.
What Is Gravity Casting?
Gravity casting (also called permanent‑mold casting) is a way to make metal parts by pouring molten metal into a reusable steel die using nothing but gravity — no high‑pressure injection needed. The metal fills the mold slowly and solidifies against a chilled steel wall, which produces denser, stronger parts with far less internal porosity than high‑pressure die casting.
That matters because low porosity means your parts can be T6 heat‑treated for extra strength and are naturally pressure‑tight — no leaking under hydraulic or pneumatic loads. It works best with aluminum, zinc, and copper alloys, and it's the go‑to choice for medium‑volume production (roughly 500–50,000 parts per year). Meco handles gravity casting as part of our full manufacturing service, so your parts can go straight from casting to CNC machining, finishing, and assembly — without switching suppliers.
Why Choose Gravity Casting for Your Parts?
If you need strong, dense, heat‑treatable metal parts at medium volume, gravity casting is hard to beat. It's the go‑to process for automotive, aerospace, and heavy equipment manufacturers who want leak‑proof performance without the tooling cost of high‑pressure die casting.
Why Teams Choose Meco for Gravity Casting
One supplier, certified quality, lower total cost.
One Supplier, Start to Finish
Casting, machining, heat treatment, finishing, and assembly all happen through Meco. One PO, one quality system, no finger‑pointing between vendors.
Tooling That Lasts
We build H13 steel dies designed for 50,000–200,000+ shots. Our tooling engineers optimize gating, risers, and cooling channels before cutting steel.
Design Feedback Before You Commit
Our engineers review your part for wall thickness, draft angles, and core requirements — and suggest changes that can cut 15–30% off your production cost.
Certified Quality
IATF 16949:2016 governs every step. PPAP, APQP, SPC, X‑ray NDT, and CMM inspection are standard — not add‑ons.
What We Can Cast
From structural brackets to pressure‑tight manifolds — we have the pouring methods and alloy know‑how to match.
Static‑Pour Gravity Casting
The standard approach — molten metal pours into a fixed steel die through a runner system designed for smooth, controlled fill. Great for symmetrical parts, brackets, and housings.
- Parts up to 25 kg
- Sand cores for internal passages
Tilt‑Pour (Durville) Casting
The machine tilts during pouring for laminar flow — less turbulence, less porosity, and better material yield. The best choice for pressure‑tight or safety‑critical parts.
- Lower porosity than static pour
- Ideal for hydraulic & fluid parts
Secondary Operations
Most gravity castings need a little extra work. We handle T6 heat treatment, CNC machining of critical features, tapping, shot‑blasting, and surface finishing — all in‑house.
- CNC machining of mating surfaces
- Powder coating, anodizing, plating
Gravity Casting Parts Gallery
Gravity Casting Alloys & Specifications
Aluminum Alloys
| A356 (T6) | 38 ksi tensile · 80 HB · structural, pressure‑tight |
| A357 (T6) | 45 ksi tensile · 90 HB · aerospace, high‑stress |
| 319 (T6) | 36 ksi tensile · 80 HB · engine blocks, manifolds |
| 535 | 35 ksi tensile · 60 HB · marine, corrosion‑critical |
Copper & Zinc Alloys
| C876 Copper | 45 ksi tensile · electrical & plumbing fittings |
| ZA‑12 Zinc | 59 ksi tensile · bearings, wear‑resistant parts |
| ZA‑27 Zinc | 62 ksi tensile · high‑strength structural |
Gravity Casting Tolerances
| Dimension Length | Standard (As‑Cast) | Precision (Post‑Machining) |
|---|---|---|
| Basic (up to 1″) | ± 0.015″ | ± 0.005″ |
| Add per inch (>1″) | ± 0.003″ | ± 0.001″ |
| Example (5″ part) | ± 0.027″ | ± 0.009″ |
| Example (12″ part) | ± 0.048″ | ± 0.016″ |
| Surface Dimension | Standard | Precision |
|---|---|---|
| Up to 3 inches | 0.010″ | 0.006″ |
| Add per inch (>3″) | 0.004″ | 0.002″ |
| Max Deviation | Based on diagonal | Requires machining |
| Feature Type | Draft Angle | Why |
|---|---|---|
| Outside Walls | 1° to 2° | Shrinkage pulls part away from cavity |
| Inside Walls | 2° to 3° | Shrinkage tightens part onto core |
| Sand Core Holes | 3° per side | Prevents core breakage at extraction |
Have a design you'd like us to look at?
Send Us Your Files — We'll Review It Free →Gravity Casting vs Other Casting Methods
Not sure which process fits? Here's a plain‑English comparison so you can decide quickly.
| Feature | Gravity Casting | Die Casting (HPDC) | Sand Casting | Investment Casting |
|---|---|---|---|---|
| Best Volume | 500 – 50,000/yr | 10,000+/yr | 1 – 5,000/yr | 100 – 10,000/yr |
| Tooling Cost | $5K – $40K | $15K – $150K+ | $500 – $7.5K | $600 – $30K |
| Mechanical Props | Excellent (dense) | Good (prone to porosity) | Fair (coarse grain) | Very Good |
| Wall Thickness | ≥ 3 mm | < 5 mm (thin walls) | Any (thick OK) | 0.5 mm+ |
| Surface Finish | Good – Excellent | Excellent | Fair – Poor | Excellent |
| Heat Treatable? | Yes (T6) | Limited | Yes | Yes |
| Best For | Pressure‑tight & high‑strength | Complex thin‑wall, high vol. | Large / simple shapes | Complex geometry |
Need More Than Casting?
We also offer die casting, sand casting, low‑pressure casting, CNC machining, stamping, forging, and assembly — all managed from one place.
Industries We Serve with Gravity Casting
From engine blocks to LED housings — if it needs to be dense, pressure‑tight, and made in medium volume, gravity casting is usually the answer.
Automotive Parts Manufacturing
Gravity‑cast aluminum engine heads, intake manifolds, and structural brackets deliver the density and heat‑treatability that high‑pressure die castings can't match. Perfect for medium‑volume programs where mechanical performance is non‑negotiable.
Aerospace Parts Manufacturing
Low‑porosity castings in A357‑T6 meet the strength and NDT requirements of aerospace programs. Every part ships with full material certification, first‑article inspection per AS9102, and lot‑level traceability.
Heavy Equipment Manufacturing
Pressure‑tight gravity castings for hydraulic manifolds, gear housings, and valve blocks that perform under continuous load, vibration, and fluid pressure. Every batch is X‑ray inspected and leak‑tested.
Industrial Machinery
Gravity castings for pump bodies, compressor housings, and pneumatic manifolds where internal porosity means product failure. Every batch is X‑ray inspected and pressure‑tested before shipment.
Marine & Offshore
Corrosion‑resistant 535 aluminum castings for marine fittings, through‑hull valves, and deck hardware. Cast to near‑net shape, then CNC machined and anodized for long‑term saltwater exposure.
Renewable Energy
Gravity‑cast aluminum housings for solar inverters, wind turbine junction boxes, and EV charging stations — T6 heat‑treated, pressure‑tested, and sealed for outdoor IP protection.
Electrical & Power Generation
Dense, EMI‑shielding enclosures and high‑conductivity connector housings cast in aluminum or copper alloy, finished and assembled to spec. Low porosity ensures consistent electrical performance.
Home Appliances
Dense, corrosion‑resistant castings for motor housings, compressor bodies, and structural appliance frames that need consistent quality at medium volume. T6 heat‑treated for long product life.
Quality You Can Verify
Every gravity‑cast part ships with full traceability and documentation. Our IATF 16949:2016 quality system covers every step — from incoming alloy to packed shipment. X‑ray NDT and helium leak testing are standard for pressure‑critical parts.
Dimensional Inspection
CMM verification to ± 0.002″ on critical features. Full GD&T evaluation with graphical deviation reports.
First Article Inspection
FAI reports per AS9102 with complete dimensional data against your drawing — before production starts.
X‑Ray & Leak Testing
Radiographic NDT for internal porosity detection. Helium leak testing for hydraulic and pressure‑critical parts.
Full Traceability
Lot‑level tracking from raw alloy through casting, heat treatment, machining, finishing, and packing. Complete audit trail.
Gravity Casting FAQ
What metals can you gravity cast?
Primarily aluminum alloys — A356, A357, 319, and 535 — which are ideal for T6 heat treatment. We also cast zinc (ZA‑12, ZA‑27) and copper alloys for bearings, electrical fittings, and plumbing components.
How much does gravity casting tooling cost?
Gravity‑casting dies typically run $5,000–$40,000 depending on part size and complexity. That's significantly less than high‑pressure die‑casting tooling ($15K–$150K+), and each die lasts 50,000–200,000+ shots.
What's the minimum order quantity?
We usually start at 500 pieces per run. The sweet spot for gravity casting is 500–50,000 parts per year — that's where unit economics are best versus other casting methods. Below 500, sand casting or CNC machining is often cheaper.
How accurate is gravity casting?
As‑cast tolerances are typically ± 0.015″ for the first inch, plus ± 0.003″ per additional inch. We tighten that to ± 0.005″ (or better) with post‑cast CNC machining on critical dimensions.
How long does it take to get parts?
Tooling takes 4–8 weeks depending on complexity. After samples are approved, production runs ship in 3–5 weeks. Rush options are available.
Can you heat‑treat gravity castings?
Yes — that's one of gravity casting's biggest advantages over high‑pressure die casting. Castings in A356 and A357 are routinely T6 heat‑treated to boost tensile strength and hardness significantly.
Do you handle finishing and assembly?
Yes. We offer shot‑blasting, tumbling, anodizing, powder coating, wet painting, chromate conversion, CNC machining, thread tapping, and mechanical assembly — all in‑house.
What file formats do you accept?
STEP (.stp) and IGES (.igs) for 3D models. PDF or DWG for 2D drawings with tolerances, GD&T, and finish callouts. We also accept Parasolid and native SolidWorks files.
Gravity casting vs die casting — when should I choose gravity?
Choose gravity when you need superior mechanical properties, pressure‑tightness, or T6 heat treatment. Choose high‑pressure die casting when you need thin walls (< 3 mm), complex geometry at very high volumes (10K+/yr), or the fastest cycle times.
How to Get Started
Upload a STEP or IGES file with material and volume info via our quote form. We respond within 24 hours.
Our engineers evaluate wall thickness, draft angles, gating design, and core requirements — then send you a detailed quote with cost‑saving suggestions.
We build your steel die, run sample castings, and send first articles for your approval before committing to full production.
Full production with in‑process inspection, X‑ray NDT, quality docs, and on‑time shipping. 99.8% on‑time delivery rate.
Gravity Casting Resources
What Is Gravity Die Casting? Process Explained
A plain‑English walkthrough of how gravity casting works, when to use it, and how it stacks up against high‑pressure die casting and sand casting.
Read the guide →
What Is a Die in Manufacturing?
A complete explainer on die types — stamping, casting, forging, and extrusion — and how to pick the right one for your project.
Compare methods →
How Much Does a Metal Part Cost in 2026?
CNC, die casting, gravity casting, forging, and stamping compared side by side with real dollar ranges and volume breakpoints.
Read the guide →Get Your Free Quote
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