MANUFACTURING PROCESS
Investment Casting
Discover high-precision, near-net-shape components with intricate geometries and excellent surface finishes.
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Custom Metal Component Manufacturing Services in China
Custom Metal Component Manufacturing: Choose the Route Around the Finished Part
A drawing does not always point to one obvious process. Tianhui compares investment casting, sand casting, die casting, forging and CNC machining against part geometry, material, expected volume, tolerance, tooling, secondary operations and validation requirements before the manufacturing route is fixed.
01 / Core Manufacturing Processes
Five Manufacturing Services for Different Part Requirements
Explore our investment casting, sand casting, die casting, forging and CNC machining services for detailed capability, DFM, tooling, secondary operations, quality controls and typical applications.
MANUFACTURING PROCESS
Sand Casting
Ideal for large, heavy-duty metal components with flexible production volumes and cost-effective tooling.
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MANUFACTURING PROCESS
Die Casting
Efficient high-volume production delivering durable, thin-walled parts with tight tolerances and smooth surfaces.
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MANUFACTURING PROCESS
CNC Machining
Achieve extreme precision, tight tolerances, and custom geometries for both quick prototypes and production runs.
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MANUFACTURING PROCESS
Forging
Engineered for maximum mechanical strength, fatigue resistance, and structural integrity under high-stress applications.
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02 / Process Comparison
Shortlist the Process by Trade-Off, Not by Process Name
More than one route may be technically possible. The comparison below shows where each process is strongest, the main cost or risk trade-offs, and which alternative routes may also be worth evaluating.
| Process | Choose It When | Key Trade-Off / Watch Point | Reference Capability | Also Compare With |
|---|---|---|---|---|
| Investment Casting | Complex alloy geometry, finer features and near-net shapes can reduce machining from solid or simplify multi-feature parts. | Tooling and shell process add lead time; achievable casting tolerance and wall section still depend on part size, alloy and geometry. | 0.05–60 kg · ≥3 mm wall · CT6–CT10 · Ra ≤6.3 μm · up to 500 × 500 × 800 mm. | CNC from solid for prototypes/low volume; sand casting for larger sections; die casting for repeat non-ferrous volume. |
| Sand Casting | Parts are larger, heavier or core-intensive and practical tooling economics matter more than fine as-cast finish. | Rougher surface and broader casting tolerances normally mean more attention to machining stock, cores, feeding and functional testing. | Up to 1,000 kg · ≥5 mm wall · CT10–CT13 · raw sample typically about 25 days. | Investment casting for finer smaller geometry; forging for strength-critical shapes; CNC for low-volume simple geometry. |
| Die Casting | Non-ferrous components have stable geometry and repeat volume high enough to justify production tooling and short cycle times. | Higher tooling commitment requires early DFM around draft, parting, ejection, wall thickness and porosity-sensitive functional zones. | 160–1250 T · ≥2.0 mm wall · GB/T 15114-2023 CT7 · up to 900 × 800 × 350 mm. | CNC for prototype/low volume; investment casting where steel/alloy choice or geometry is more important than cycle rate. |
| Forging | The part is load-bearing, fatigue-sensitive or strength-critical and material flow can improve mechanical performance. | Preform/tooling design and heat treatment must be considered together with machining allowance and geometry limitations. | 0.5–50 kg · approx. 300 × 450 mm · presses up to 1600 T · CT10–CT14. | Casting for more complex internal geometry; CNC from stock for development quantities or shapes that do not justify forging tooling. |
| CNC Machining | Prototype or lower-volume demand, tight finished dimensions, datum relationships or critical bores/interfaces drive the part. | Machining from solid can increase material waste, cycle time and setup cost as geometry or volume grows; a near-net blank may lower total cost. | 35 machines · 3/4/5-axis · 400 × 1000 × 800 mm travel · 150 kg · ISO 2768-mK · Ra 0.8–3.2 μm. | Investment/sand casting or forging + CNC when repeat volume makes near-net material use and reduced machining attractive. |
Selection ruleCompare the complete route: tooling amortization + material yield + cycle time + machining stock + setup count + heat treatment/finishing + inspection + expected repeat volume. The lowest blank price is not always the lowest finished-part cost.
03 / Manufacturing Route Selection
Six Questions That Usually Decide the Route
These questions narrow the process choice before quotation. They also help separate features that must be created in the primary process from features that are better finished by machining or secondary operations.
What Does the Geometry Demand?
Cores, internal passages, undercuts, wall transitions, large sections and machining access can eliminate otherwise attractive routes.
What Must the Material Do?
Corrosion resistance, fatigue, strength, temperature and wear requirements determine which alloys—and therefore which processes—remain practical.
Will the Volume Repay Tooling?
Prototype and low-volume work often favors flexible routes; repeat demand can justify tooling that reduces cycle time, material use or machining.
Which Features Truly Need Machining?
Define datums, sealing faces, bores, threads, fits and roughness separately from features that can remain as-cast or as-forged.
What Happens After the Blank?
Heat treatment, coating, NDT, pressure/leak testing, balancing, assembly and documentation can change which primary process is most efficient.
What Is the Finished-Part Cost?
Compare tooling, material yield, machining stock, setup time, scrap/rework risk, inspection and repeat volume—not only the price of the blank.
Practical approachIf two routes remain viable, quote or prototype the route with the greatest uncertainty first. The objective is to remove technical risk before optimizing unit price.
04 / Typical Route Patterns
The Process Choice Changes What Happens Next
These are route patterns, not fixed recipes. The drawing and validation requirements determine which steps are kept, removed or reordered for the actual component.
Complex Alloy Geometry
Investment casting → controlled machining stock → CNC of critical interfaces → heat treatment/finishing where required → final inspection.
Large or Core-Intensive Part
Sand casting → cleaning/heat treatment as required → CNC of datums, bores and sealing faces → pressure/leak or other functional checks where specified.
Repeat Non-Ferrous Production
Die casting → trimming/deburring → targeted CNC machining → coating/finishing → batch dimensional and functional verification.
Load- or Fatigue-Critical Part
Forging → heat treatment → CNC machining → hardness/mechanical verification and NDT where required → finishing and release.
Prototype, Low Volume or Tolerance-Led Part
CNC machining from solid or an existing blank → in-process inspection → finishing. If volume rises, compare a cast or forged near-net blank before scaling.
05 / Secondary Operations & Finished-Part Supply
Build Secondary Operations Around the Required Delivery Condition
Depending on the part, Tianhui can coordinate raw-part supply, rough machining or completed components with agreed heat treatment, finishing, testing and inspection.
CNC Machining
Finish datums, bores, sealing faces, threads, interfaces and other critical features after casting or forging.
Heat Treatment
Coordinate specified heat-treatment routes around alloy, hardness and mechanical requirements.
Surface Finishing
Support blasting, polishing, passivation, coating and other finishing requirements according to the drawing.
Inspection & NDT
Plan dimensional, material, hardness and project-specific NDT requirements according to part risk and specification.
Functional Testing
Pressure, leakage, balance, torque or application-related checks can be reviewed where relevant to the component.
Assembly, Marking & Packaging
Review sub-assembly, part marking, preservation and export packaging requirements before shipment.
Scope noteNot every secondary operation is performed in-house. Where specialist processes are required, the production and inspection scope can be coordinated with qualified external partners and defined during quotation.
06 / Quality & Documentation
View Quality Control → Inspection and Documentation Follow the Critical Requirements
Inspection is most useful when it is connected to drawing risk, process risk and the final function of the component.
Material Verification
Material grade, chemistry or related documentation can be checked according to the agreed project scope.
Dimensional Inspection
CMM, measuring equipment and gauges are applied according to critical dimensions, datums and drawing requirements.
Process-Specific Testing
Hardness, surface, NDT, pressure/leak or other tests are selected where relevant to the process and application.
Project Documentation
Inspection reports, material records, traceability, FAI or PPAP documentation can be reviewed where the customer requires them.
07 / Selected Manufacturing Cases
All Case Studies → See How Process Choices Work on Actual Components
Case studies show the relationship between material, forming route, machining, critical features and inspection on real manufacturing projects.
CASE STUDY
Cast Iron Metering Pump Housing
Cast iron metering pump housing combining casting and precision machining, with a φ19H7 × 230 mm deep bore, selected IT7 dimensions, Ra 0.4 surface finish and d...
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CASE STUDY
42CrMo Forged And Machined Cam
42CrMo forged and machined cam produced through forging, precision machining and heat treatment, controlling IT7 features, Ra 1.6 finish, 8H spline and HRC 56–6...
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CASE STUDY
316L Stainless Steel Hydraulic Metering Diaphragm Pump Head
316L stainless steel diaphragm pump head produced with precision casting and CNC machining, controlling CT7 casting accuracy, IT7 features, Ra 0.8 finish and a ...
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08 / What to Send
Information Needed for a Manufacturing Review
A complete RFQ reduces assumptions and helps define process, tooling, machining and inspection scope more accurately.
Manufacturing Solution Review
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Send Us Your Drawing for an Optimized Manufacturing Route
From casting and forging to precision CNC machining, TIANHUI MACHINE provides integrated manufacturing services for custom metal components. Our China factory supports different materials, geometries and production volumes, helping OEM customers select an efficient manufacturing process and achieve reliable quality from prototype to production.
Send your drawing, 3D model, material, quantity, critical tolerances and delivery requirements. We will compare feasible manufacturing routes, identify process and cost optimization opportunities, and define how forming, machining, finishing and inspection can be integrated into one coordinated solution.