Low Pressure Die Casting Manufacturer
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Your Best Low Pressure Die Casting Supplier in China.
Solving Your Manufacturing Challenges with LPDC
IEC Mould specializes in precision low pressure die casting for complex aluminum parts across automotive, aerospace, and industrial sectors. We provide a full range of services, including mold design, casting, CNC machining, and surface finishing all in-house. With our controlled LPDC process, you benefit from:
- Low porosity & high structural strength
- Consistent dimensional accuracy
- Fewer defects, less rework
- Shorter lead times & reduced costs
Our advanced equipment and strict quality control ensure stable, repeatable results for every project — whether you need large structural components or fine, detailed castings. Partner with IEC Mould to streamline your production, reduce supplier risk, and get castings that meet your exact specifications — delivered on time.
What is Low Pressure Die Casting?
Low Pressure Die Casting (LPDC) is a permanent mold casting process in which molten metal is gently filled from the bottom of the die using low gas pressure（0.7-1.5 bar). This bottom-fed, controlled filling minimizes turbulence, reduces porosity, and enables directional solidification, resulting in high-integrity aluminum components.
Unlike High Pressure Die Casting (HPDC), which uses extremely high injection pressures to fill the mold rapidly, LPDC’s controlled filling and solidification allow for heat-treatable parts, thicker wall sections, and excellent mechanical properties. For these reasons, LPDC is commonly used in automotive structural parts, wheels, suspension arms, industrial housings, and other critical applications requiring leak-tightness and strength.
Why Choose LPDC?
🧠 Engineers
Reliable mechanical performance for structural components
Compatible with FEA, load-bearing design, and fatigue analysis
Predictable heat treatment outcomes (T5/T6)
🕵️ Quality Control (QC) Professionals
Stable, repeatable process with reduced internal defects
Full traceability, documentation, and inspection reports
In-house X-ray, CMM, pressure test, and spectrometry
💼 Procurement Teams
- Fast lead times & high-volume efficiency
- Competitive cost-per-part
- One-stop mold-to-assembly service
📦 Product Managers / Founders
One-stop service from DFM to assembly
Scalable from prototypes to 500,000+ units/year
Faster time-to-market with design optimization support
How Low Pressure Die Casting Works?
Low Pressure Die Casting (LPDC) is a precise and controlled casting process that uses low-pressure air to force molten metal into a reusable metal die. Unlike gravity casting, LPDC offers better control over metal flow, resulting in high-quality castings with excellent mechanical properties and minimal porosity. Here is a step-by-step breakdown of how LPDC works:
Step 1. Mold Preparation and Preheating
The process begins with the preparation of the metal mold (die). The die is thoroughly cleaned and preheated to an optimal temperature, usually around 200°C to 300°C. Preheating helps to Ensure proper metal flow + Reduce thermal shock + Improve surface finish and consistency.
Step 2: Molten Metal Holding Furnace Setup
Below the die, a sealed holding furnace is filled with molten metal. A ceramic riser tube extends vertically from the furnace to the die cavity above. The furnace is kept at a stable temperature to maintain metal fluidity and avoid oxidation. The riser tube is submerged in the molten metal and connects directly to the gate system of the die.
Step 3: Application of Low Pressure
Once everything is in place, low pressure air (usually 0.3 to 1.5 bar) is gradually applied to the sealed holding furnace. This pressure forces the molten metal up through the riser tube and into the die cavity from the bottom up.
Step 4: Die Cavity Filling
The molten metal fills the cavity slowly and evenly under constant low pressure. Because the metal enters from the bottom and rises to the top, it gently displaces the air inside the cavity, allowing for a clean and complete fill.This process is particularly beneficial for components with complex geometries or thin wall sections, where precise flow control is essential to avoid defects.
Step 5: Solidification Under Pressure
After the mold is completely filled, the applied pressure is maintained. This helps to compensate for any metal shrinkage during solidification and ensures that the metal remains in full contact with the die walls. Solidification starts from the farthest point in the cavity and proceeds directionally toward the riser tube. This directional solidification: Improves structural integrity + Reduces shrinkage porosity + Enhances the density + strength of the casting
Step 6. Cooling and Ejection
Once the casting has fully solidified, the pressure is released and the die is allowed to cool further. The mold is then opened, and the solidified casting is ejected using ejector pins. Because LPDC uses a permanent metal mold, the die can be reused for multiple cycles after applying appropriate die release agents and re-cleaning.
Step 7. CNC Machining & Post-processing
Trimming, threading, and machining to final tolerance.
Step 8. Surface Treatment & Final QA Inspection
Options include anodizing, powder coating, chromate, shot blasting, polishing. X-ray, leak test, CMM, dimensional reports, microstructure validation.
Key Advantages of Low Pressure Die Casting
| Advantage | For Engineers | For Procurement Teams | For Quality Control (QC) |
|---|---|---|---|
| Excellent Dimensional Accuracy (±0.1 mm) | Ensures design intent is met with minimal redesign or adjustments. | Reduces need for extra machining, lowering cost per part. | Easier to verify part dimensions, reducing inspection time. |
| Large & Complex Part Capability | Enables creation of lightweight, high-strength structural parts. | Consolidates multiple components into one casting, lowering sourcing complexity. | Fewer assembly points mean fewer potential defect locations. |
| Low Gas Porosity | Improves mechanical performance and heat-treatability of parts. | Reduces warranty claims and returns due to internal defects. | Higher pass rate during X-ray or ultrasonic inspections. |
| Thin-Wall Designs with Strength | Achieves weight reduction without sacrificing performance. | Lower material usage reduces cost and supports sustainability goals. | Maintains part integrity during quality stress tests. |
| Extended Mold Life | Consistent mold performance ensures repeatable results over long runs. | Lowers tooling replacement costs and increases ROI. | Fewer dimensional deviations due to worn tooling. |
| Reduced Machining Requirements | Shortens development cycle by minimizing post-processing steps. | Speeds up delivery schedules for customer orders. | Less chance for defects introduced during secondary machining. |
| Material Versatility | Flexibility to choose alloys for specific application needs. | Ability to switch alloys without major tooling changes. | Consistent inspection parameters across different materials. |
| Heat-Treatable, Dense Parts | Allows use of T6 and similar treatments for enhanced strength. | Expands product applications to higher-value markets. | Ensures parts pass fatigue and stress tests. |
| Lower Energy Consumption | Supports sustainable engineering projects. | Reduces operational costs over large-scale production. | Helps achieve sustainability KPIs for production quality metrics. |
| Global Standards Compliance | Meets ISO, ASTM, JIS requirements for global markets. | Simplifies cross-border sourcing and logistics. | Consistent quality regardless of destination market. |
LPDC vs Other Casting Methods
✅ LPDC is the preferred process for mission-critical parts that must withstand pressure, heat, and structural loads — such as wheels, suspension components, housings, and battery frames.
| Feature | LPDC | HPDC | Gravity Die Casting | Sand Casting |
|---|---|---|---|---|
| Filling Pressure | Low (0.7–1.5 bar) | Very High (1000+ bar) | Gravity only | Gravity only |
| Porosity | ✅ Low | ❌ High | ⚠️ Moderate | ❌ High |
| Heat Treatment | ✅ T5/T6 Applicable | ❌ Often not possible | ✅ Yes | ✅ Yes |
| Surface Finish | ⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐ | ⭐ |
| Design Flexibility | ⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐ | ⭐ |
| Ideal for | Structural, leak-tight parts | Thin-wall high-volume parts | Simple shapes | Large prototypes |
LPDC Part Applications Across Industries
🚗 Automotive & NEV
- Aluminum wheels
- Suspension arms & crossmembers
- Motor housings
- Inverter enclosures
- Battery trays and pack housings
🛫 Aerospace
- Interior structure parts
- Mounting brackets
- Avionics enclosures
⚡ Energy & Electrical
- Heat sinks and cooling components
- Power inverter cases
- Junction boxes
🏭 Industrial Equipment
- Hydraulic housings
- Gearbox covers
- Pump and valve bodies
Materials We Use for LPDC
| Alloy | Properties | Common Uses |
|---|---|---|
| A356 / A356-T6 | High strength, low porosity, heat-treatable | Auto wheels, battery trays |
| AlSi10Mg | Excellent castability & corrosion resistance | NEV parts, cooling housings |
| A319 | Good machinability & strength | Gearboxes, engine covers |
| ZL101 / ZL104 | Chinese standard, good pressure resistance | Suspension parts, brackets |
Common Technical Specifications – Low Pressure Die Casting (LPDC)
Filling Pressure: LPDC typically operates at 0.7 to 1.5 bar of controlled gas pressure, gently pushing molten metal from the holding furnace into the mold. This low turbulence filling greatly reduces oxide formation and internal defects.
Cycle Time: LPDC cycle times usually range from 2 to 5 minutes, depending on the complexity and size of the casting. The process is slower than HPDC but offers higher quality and structural integrity.
Alloy Selection: Common alloys include A356, 6061, 319, and other heat-treatable aluminum alloys. These materials offer excellent mechanical properties, corrosion resistance, and weldability.
Wall Thickness: LPDC can produce wall thicknesses down to 3 mm, with uniform and consistent density across the casting.
Tolerances: LPDC typically achieves ±0.15 mm to ±0.25 mm tolerances — slightly wider than HPDC but with superior mechanical properties and heat treat capability.
Common Challenges and Solutions – Low Pressure Die Casting (LPDC)
Slower Cycle Times: Compared to HPDC, LPDC is slower, which can impact throughput.
Solution: Optimize mold design and use multi-cavity tooling to increase output without compromising quality.Tooling Complexity: LPDC tooling must be designed for vertical filling and low-pressure feeding systems, which can be more complex.
Solution: Utilize advanced simulation tools like MOLDFLOW and thermal analysis to optimize gate and riser placement for defect-free parts.Surface Finish Variation: LPDC can produce slightly rougher surfaces than HPDC.
Solution: Apply precision machining or finishing processes (shot blasting, anodizing, powder coating) to meet aesthetic and dimensional requirements.Porosity from Gas Entrapment: Although less common than in HPDC, porosity can still occur if filling is not perfectly controlled.
Solution: Maintain strict control of furnace atmosphere, metal cleanliness, and filling speed to minimize gas inclusion.
Why Engineers and Buyers Trust Us
- ✅ Over 20 years of die casting experience
- ✅ In-house mold, casting, machining & finishing
- ✅ Certified under ISO 9001 / IATF 16949
- ✅ Fluent English technical support
- ✅ Real-time updates with photos/videos of production
- ✅ Strict project confidentiality & IP protection
How to Work With Us
- ✅ Send Us Your Drawing or Idea
- ✅ Receive Free DFM Feedback
- ✅ We Quote Within 24 Hours
- ✅ Rapid Prototyping or Tooling Starts
- ✅ PPAP or Sample Approval
- ✅ Mass Production & Global Delivery
Low Pressure Die Casting Frequently Questions & Answers
What types of parts and industries is LPDC best suited for?
LPDC excels at producing structurally critical, leak-tight aluminum parts with complex geometries, such as automotive suspension components, aerospace brackets, energy battery trays, and industrial housings.
How does LPDC ensure high quality and low defect rates?
By using low, controlled pressure for metal filling, combined with degassing, filtration, and precise temperature control, LPDC minimizes porosity and shrinkage. We also employ advanced inspection methods including X-ray, CMM, and pressure testing to guarantee part integrity.
What alloys are compatible with LPDC and can they be heat treated?
Common alloys include A356, A357, 319, and magnesium AZ91, all of which support heat treatments like T5 and T6 to improve strength, hardness, and fatigue resistance—critical for demanding applications.
What are typical dimensional tolerances and surface finishes achievable with LPDC?
LPDC provides dimensional tolerances around ±0.15 to ±0.25 mm, suitable for tight-fitting assemblies. Surface finishes are smooth, often requiring minimal post-processing such as machining or coating.
What is the typical lead time and minimum order quantity (MOQ) for LPDC projects?
We offer flexible production starting from as low as 50 pieces, with lead times usually between 4 to 8 weeks depending on complexity and order size. Our in-house tooling and process controls ensure reliable delivery schedules.
How does LPDC compare cost-wise to other casting methods like HPDC or sand casting?
LPDC balances tooling cost and part quality effectively, offering lower defect rates and better mechanical properties than sand casting, with tooling costs and cycle times generally lower than HPDC for medium-sized parts and volumes.
How do you support customers throughout the LPDC production process?
We provide end-to-end services including DFM consultation, mold design & manufacturing, MOLDFLOW simulation, casting production, CNC machining, surface treatment, quality inspection, and assembly—ensuring your parts meet exact requirements on time and budget.
