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Investment Casting — Precision Lost-Wax Castings & Custom Metal Components
What is Investment Casting?
Investment casting, also called lost-wax casting, is a precision metal casting process for producing complex, near-net-shape parts with excellent surface finish and tight dimensional accuracy. The process begins with a wax pattern (often produced by injection molding or 3D printing), which is assembled into a tree and coated with ceramic slurry to form a rigid shell. After the ceramic cures, the wax is melted out (dewaxing). Molten metal is poured into the ceramic mold to form the final part; once cooled, the shell is removed and the castings undergo finishing and any required machining. Investment casting minimizes material waste and often reduces or eliminates the need for extensive secondary machining.
Materials We Work With
We cast a wide range of alloys to match performance, environment and regulatory needs. Typical materials we handle include:
Advantages: Excellent corrosion resistance, good mechanical strength, and biocompatibility for medical parts.
Common uses: Valve bodies, pump parts, medical housings, and food-grade components.
Carbon & Alloy Steels (ASTM 1020, 20Cr, 40Cr)
Advantages: High toughness and wear resistance; can be heat treated for added hardness.
Common uses: Heavy-duty fittings, industrial machinery parts, tailors for pressure applications.
Nickel-Based Alloys (Inconel, Hastelloy and others)
Advantages: Exceptional high-temperature strength and oxidation resistance.
Common uses: Aerospace turbine components, energy sector parts, and high-temperature valves.
Aluminum Alloys (A356-T6, ADC12, A380)
Advantages: Lightweight, good thermal conductivity and corrosion resistance.
Common uses: Automotive parts, lightweight housings and components needing good surface finish.
Special Alloys & Bronze
For each job we recommend the optimal alloy based on design, operating environment and cost — and we can provide material certificates with sample deliveries.
Industries & Typical Applications
Investment casting is chosen where precision, surface quality and complex geometry matter. Representative industries and examples:
Aerospace: turbine blades, structural brackets, and high-temperature engine parts requiring tight tolerances and reliable metallurgy.
Medical & Dental: surgical instruments, orthopedic implants and precision housings where surface finish and biocompatibility are critical.
Automotive & New Energy Vehicles: transmission components, exhaust parts and structural castings optimized for weight and durability.
Energy & Power: valve bodies, pump housings and heat-resistant components for oil, gas and power generation.
Industrial Machinery: precision pump parts, fittings, poppets and custom conversion joints for demanding environments.
Consumer & Commercial Hardware: decorative handles, aerators, and precision cast housings with plating or electro-polished finishes.
Examples of parts we produce include CF8M stainless housings, electro-polished aerators, precision poppets, conversion joints, and non-standard stainless castings with CNC finish.
Comparison: Investment Casting vs Sand Casting vs Machining
Choosing the right manufacturing method depends on geometry, surface finish, tolerance, volume and cost. Here’s a concise comparison:
Investment Casting
Surface finish: Excellent — usually requires minimal finishing.
Precision: High — tight tolerances and fine features achievable.
Complexity: Excellent — thin walls, internal passages and detailed features possible.
Best when: You need complex geometry, good surface finish, and near-net-shape parts that reduce downstream machining.
Surface finish: Coarser — more finishing required.
Precision: Lower — larger tolerances, suited to larger parts.
Complexity: Moderate — good for large, less intricate parts.
Best when: Large parts, lower cost tooling, or when tight tolerance is not essential.
Surface finish: Excellent (after finishing).
Precision: Very high — can achieve micron-level tolerances.
Complexity: Limited by tool access — internal cavities and extremely intricate forms can be costly or impossible.
Best when: Parts require very tight tolerances, individual prototypes, or simple geometry from billet/forging material.
Bottom line: Investment casting is the preferred choice when you need complex geometries and excellent as-cast surfaces with reduced machining. Sand casting is cost-effective for large, simple parts. CNC machining is best for ultimate tolerances or when a part is derived from solid stock.
Our Capabilities & Equipment
NBI delivers end-to-end investment casting services customized to your drawings and requirements:
Pattern & tooling: Wax pattern production, rapid prototyping (3D printed patterns) and tooling services.
Ceramic shell & casting: Controlled shell-making, dewaxing, and precise metal pouring processes.
Post-processing: Shot-blasting, sand-blasting, electro-polishing, electroless nickel plating, zinc plating, and passivation.
CNC finishing: In-house CNC machining to tight tolerances when required for critical features.
Assembly: Sub-assemblies, installation of inserts, O-rings, and pre-assembly per your specifications.
Batch flexibility: Prototyping and small runs to higher volume production with process repeatability.
Quality Control & Traceability
We enforce strict quality protocols to meet industry demands:
Material traceability: Mill certificates and material reports included with samples.
Dimensional inspection: First article inspection, in-process checks and final CMM verification.
Documentation: Sample inspection reports, production traceability and customer-required QA paperwork (PPAP/FAI style deliverables available).
Surface & metallurgical tests: Surface finish inspection, hardness testing and chemical analysis on request.
Why Choose NBI?
Technical experience: Years of hands-on skill in investment casting — from prototype patterns to production casting.
Integrated services: Pattern making → casting → CNC finishing → surface treatment → assembly. One supplier reduces coordination, lead times and costs.
Material breadth: Capability to cast stainless steels, carbon & alloy steels, nickel superalloys and aluminum alloys to match demanding specs.
Quality & traceability: CMM inspection, material certificates and sample reports ensure you get what the drawing specifies.
Customer support: DFM feedback, rapid quoting, sample services and technical support from design through after-sales.
Application focus: Experience serving aerospace, medical, automotive, energy and industrial markets with parts that must perform reliably.
Future Trends & Innovation
We embrace digital simulation, additive pattern production, greener binders and reclaimed materials to improve yields, reduce lead time and lower environmental impact. Our R&D continues to evaluate new alloys and refractory materials for higher durability and performance.
Ready to Start Your Project?
Send us your drawing (STEP, DWG or PDF) for a free DFM review and fast quote. We provide sample material certificates and a full dimensional report with prototype deliveries.
Start Your Project
