Custom OEM metal casting components deliver structural integrity, precise dimensional control, and near-net-shape geometry for industrial equipment, fluid handling systems, heavy machinery, automotive assemblies, and chemical processing hardware.
Utilizing investment casting (lost-wax) and precision sand casting methods, raw melt is converted into finished engineering parts ranging from 0.05 kg to 500 kg. This process minimizes raw material scrap and reduces multi-axis CNC machining cycles on complex internal channels, thin-walled structures, and contoured external profiles.
Manufacturing Process
The selection between investment casting and sand casting depends on part geometry, required dimensional tolerances, surface finish specifications, and total production volume.
Silica Sol Investment Casting (Lost-Wax)
Designed for intricate geometries, internal cross-passages, thin sections down to 2.5 mm, and tight envelope tolerances without extensive machining.
• Pattern Tooling: CNC-machined aviation-grade aluminum (AL6061/7075) dies injected with temperature-stabilized wax to maintain dimensional stability under high cycle rates.
• Tree Assembly: Individual wax patterns are hand-dressed, inspected for flash or sink marks, and gate-welded onto a central runner tree.
• Robotic Shell Building: Automated dipping into a silica sol binder slurry followed by Zircon sand stuccoing. Shells undergo 5 to 7 drying cycles under controlled humidity (50%-60% RH) and temperature (22°C - 24°C).
• Dewaxing & Firing: Steam autoclave dewaxing at 8-10 bar pressure melts the wax core quickly to prevent cracking. Shells are burned out in gas-fired kilns at 1050°C to burn off residual hydrocarbons and sinter the ceramic structure.
• Pouring & Knockout: Molten metal from medium-frequency induction furnaces is gravity-poured into pre-heated ceramic shells (950°C - 1000°C). After cooling, mechanical vibrators and high-pressure water jets break away the ceramic shell.
Resin Sand & Shell Mold Casting
Optimal for structural housings, heavy valve bodies, and large industrial components requiring medium-to-high strength where raw unit weight exceeds investment casting limits.
• Pattern & Core Box Prep: High-density aluminum or iron tooling forms the mold cavity using furan or phenolic resin sand.
• Core Setting: Hardened sand cores are positioned using location prints to establish hollow internal geometries and fluid passages.
• Pouring & Shakeout: Liquid alloy is introduced through calculated gating systems to minimize turbulent flow. Castings are shaken out, shot-blasted, and risers are removed via arc-air gouging or grinding.
Materials and Technical Specifications
All melts are analyzed via optical emission spectrometry (OES) prior to tapping to verify chemical composition against international standard ranges.
Austenitic Stainless (CF8/304, CF8M/316): Tensile strength ≥ 485 MPa, Yield ≥ 205 MPa, Hardness ≤ 200 HB. Standard to pitting-resistant grades for fluid handling and marine applications.
Martensitic Stainless (CA15/410): Tensile strength ≥ 620 MPa, Yield ≥ 450 MPa, Hardness 180-240 HB. Heat-treatable for high mechanical strength and moderate wear resistance.
Duplex Stainless (4A/2205): Tensile strength ≥ 655 MPa, Yield ≥ 450 MPa, Hardness ≤ 290 HB. Dual-phase structure offering high yield strength and stress-corrosion cracking immunity.
Carbon Steel (WCB): Tensile strength ≥ 485 MPa, Yield ≥ 250 MPa, Hardness 140-180 HB. Standard weldable structural grade for high-pressure valves, pumps, and flanges.
Low Alloy Steel (4140, 8620): Tensile strength 600–850 MPa, Yield 400–650 MPa, Hardness up to 36 HRC. Quenched and tempered or carburized for high fatigue resistance and core toughness.
Wear-Resistant Irons (High-Cr Iron ASTM A532): Tensile strength ≥ 600 MPa, Hardness 58-64 HRC. High volume of chromium carbides (M7C3) for slurry pumping and mining abrasion.
Key Product Features
Structural Integrity & Soundness: Computerized mold flow and solidification modeling (MAGMA/ProCAST) locates hot spots and shrinkage porosity prior to tooling production. Argon degassing during ladle transfer reduces dissolved gases to prevent micro-porosity.
Near-Net-Shape Precision: Investment casting maintains envelope tolerances of ±0.127 mm per 25.4 mm (±0.005 in/in), limiting CNC machining to critical bearing seats and mating faces. Complex channels are formed directly using soluble wax or ceramic cores.
Surface Quality & Markings: Zircon face coats produce smooth surface finishes (Ra 3.2 μm - 6.3 μm). Heat numbers, part numbers, and logos are directly cast onto components using raised or recessed lettering (0.5 mm profile height).
Typical Applications
Fluid Handling & Flow Control:
Pump casings, open/closed impellers, valve bodies, butterfly valve discs, strainer bodies.
Heavy Industrial Machinery:
Gearbox housings, planetary carriers, torque arms, bearing pedestals, hydraulic cylinder clevises.
Mining & Aggregate Processing:
Crusher liner plates, slurry pump wear plates, impeller hubs, chute liners, bucket teeth links.
Commercial Vehicles & Automotive:
Suspension brackets, steering knuckles, turbocharger housings, exhaust manifolds, brake calipers.
Marine & Offshore Engineering:
Propeller strut brackets, sea water strainers, pipe flanges, deck fittings, valve trim components.
Machining and Secondary Operations
Thermal Processing (Heat Treatment): Solution annealing (1040°C–1120°C with water quench), normalizing and tempering (880°C–920°C), quenching & tempering (QT up to 44 HRC), and low-temperature stress relieving (550°C–650°C).
CNC Machining Capabilities: Multi-axis CNC lathes maintain tight bore/shaft tolerances within ±0.010 mm (H7/g6 fits). 4-axis and 5-axis machining centers handle complex faces and ports. Threads (NPT, BSPT, Metric, UNC/UNF) are verified using plug and ring gauges.
Surface Finishing Treatments: Passivation and electropolishing (down to Ra 0.4 μm for sanitary applications). Stainless bead blasting and steel shot blasting (ISO 8501-1 Sa 2.5). Zinc plating, E-coat, and powder coating tested up to 960 hours per ASTM B117.
Quality Control and Inspection
Material Verification: Pre-pour OES chemistry verification with EN 10204 3.1 traceability. Tensile, yield, elongation, and Charpy V-notch impact testing (down to -40°C). Metallographic examination for microstructural phase distribution.
Dimensional Metrology: Programmable CMM equipment for positional, flatness, and profile tolerances. 3D laser scanning generates color-coded deviation maps against native STEP files for FAI.
Non-Destructive Testing (NDT): Radiographic Inspection (X-Ray per ASTM E446/E192), Dye Penetrant (PT per ASTM E165), Magnetic Particle (MT per ASTM E709), and Hydrostatic/Pneumatic pressure testing up to 200 bar.
OEM Lead Times & Support
Prototype Development:
10 to 15 business days (via 3D printed SLA wax/sand)
Tooling Fabrication:
20 to 30 calendar days (Aluminum or Steel Tooling)
First Article Sample:
7 to 10 days post-tooling completion (with PPAP Level 3)
Production Run Lead:
30 to 40 days (batch sizes from 50 to 50,000 units)
Engineering Support:
DFM reviews for draft angles (0.5° to 1.5°), radii, and wall transitions. Reverse engineering via 3D laser scanning for legacy parts.
Tooling Ownership:
Customers maintain 100% ownership of custom tooling dies, which are stored and maintained in climate-controlled facilities at no extra cost.
What Buyers Should Provide for an RFQ
Engineering Drawings: 3D Model (STEP, IGES, Parasolid) and 2D Drawing (PDF/DWG with GD&T and datum points).
Material Specifications: Exact alloy designation (e.g., ASTM A351 CF8M, 4140 Steel) and heat treatment requirements.
Quantity & Batch Sizes: Initial sample requirement and Estimated Annual Usage (EAU).
Quality & Inspection: NDT requirements (Radiography, PT/MT) and documentation needs (EN 10204 3.1, PPAP Level 3, CMM reports).
Surface & Secondary Operations: Machining scope (rough cast vs. fully machined) and coating specifications.
Frequently Asked Questions
Q: What as-cast dimensional tolerances can your investment casting process achieve?
A: Standard investment castings meet ISO 8062-3 DCTG 4 to DCTG 6 tolerances (±0.13 mm per 25 mm). Features requiring tighter limits are cast with stock allowances (0.5 mm to 1.5 mm) and CNC-machined to achieve IT7 or IT6 tolerances.
Q: How do you prevent internal shrinkage defects in thick-to-thin section transitions?
A: Thermal gradient variations are managed via solidification simulation software (MAGMA/ProCAST). Engineers place thermal risers, apply internal chills, or suggest DFM modifications like coring out thick sections to ensure directional solidification.
Q: What quality control documentation is delivered with production shipments?
A: Shipments include an EN 10204 3.1 Material Test Report (MTR), Dimensional CMM Inspection Report, Heat Treatment Time-Temperature Charts, NDT Certificates (when specified), and PPAP Level 3 Documentation for automotive or industrial product approvals.
Q: What is the typical surface finish of raw castings versus machined surfaces?
A: Raw investment castings yield Ra 3.2 μm to 6.3 μm (125–250 RMS), while precision sand castings yield Ra 12.5 μm to 25 μm. CNC milling, turning, and grinding achieve finishes down to Ra 0.8 μm to 1.6 μm, with polishing reaching Ra 0.4 μm.
Q: Can you cast hard-to-machine superalloys or wear-resistant metals?
A: Yes. Materials like high-chromium white irons (ASTM A532), duplex stainless steels (2205/2507), and nickel-based alloys are routinely cast. Near-net-shape casting minimizes material removal and tooling wear on high-hardness alloys.
Q: How do you handle tooling storage and ownership?
A: Tooling is 100% customer-owned and used exclusively for the owner's production orders. Storage, routine cleaning, preventative maintenance, and minor die repairs are managed in-house at no recurring cost.
