Home/Products/Precision Metal PartsPrecision Metal Parts Manufacturer in China

Die Casting

High-pressure die casting (HPDC) forces molten aluminum or zinc alloy into a precision-machined steel mold at velocities exceeding 50 m/s and pressures up to 800 bar. The result is a near-net-shape component with thin walls (down to 1.0 mm), complex internal geometry, and dimensional accuracy of ISO 8062 CT4–CT6 — roughly ±0.05 mm on critical features, refinable to ±0.01 mm with secondary CNC machining.

Materials and capabilities. We cast the full range of aluminum die casting alloys — ADC12, A380, A360, AlSi9Cu3, and AlSi10Mg — on machines from 280T to 900T. For zinc, we run Zamak 3 and Zamak 5, favored by consumer electronics buyers for thin-wall housings with exceptional surface finish. Vacuum-assisted die casting reduces internal porosity below 3%, essential for leak-tight automotive components like transmission housings, EV battery enclosures, and fluid pump bodies that must pass 100% air-decay leak testing.

Surface treatment. As-cast parts can receive shot blasting, powder coating, e-coating, anodizing, or electrophoretic deposition — all in-house — eliminating the quality gaps that arise when finishing is outsourced.

Where it fits. The global automotive die casting market reached $78.5 billion in 2025 and is projected to grow at 6.8% CAGR through 2034, driven by EV lightweighting and integrated structural casting. As an IATF 16949 aluminum die casting supplier, Ningbo Empire serves this demand with full PPAP Level 3 packages including PFMEA, Control Plans, MSA, and SPC data for every automotive program.

Investment Casting

Investment casting — also called lost wax casting — produces near-net-shape metal parts by dipping a wax pattern into ceramic slurry, drying it layer by layer, then dewaxing and firing the shell at 870–1,095°C before pouring molten metal. The process excels at complex geometries, thin walls, and tight tolerances that would be expensive or impossible to machine from solid stock.

Two binder systems, one decision. Our foundry runs both silica sol and water glass shell systems. Silica sol investment casting uses colloidal silica binder with zircon refractory, producing CT4–CT6 tolerances (±0.5% linear), Ra 1.6–6.3 μm as-cast surface finish, and minimum wall thickness down to 0.6 mm. It is the standard for stainless steel investment casting (304, 316, 316L, 17-4PH), duplex stainless, and nickel-based superalloys poured at 1,580–1,620°C. Water glass casting costs 25–40% less and builds shells in 2–3 days versus silica sol's 5–7 days, but tops out at CT7–CT8 tolerance and Ra 6.3–25 μm — adequate for carbon steel brackets and general industrial hardware where finish machining will cover most surfaces anyway.

Standards and materials. Stainless steel investment casting to ASTM A351 covers CF8, CF8M, and CF3M grades for valve bodies, pump impellers, and fluid system fittings. We also pour carbon steels (AISI 1020–1045), alloy steels (4140, 4130), and tool steels across five material families. Weight capacity spans 0.01 kg to 50 kg per piece for silica sol, and up to 200 kg for water glass.

Where it fits. When a part has internal channels, undercut features, or sealing surfaces that demand as-cast precision, investment casting eliminates machining operations that would otherwise dominate the total cost. For annual volumes under 1,000 pieces, silica sol is often the most economical route because tooling amortization is minimal and machining allowance shrinks to near zero.

CNC Machining

CNC machining is the backbone of our precision metal parts manufacturing — both as a standalone process for wrought stock and as the finishing operation that brings castings, extrusions, and forgings to final dimensional accuracy. Our facility operates 3-axis, 4-axis, and simultaneous 5-axis machining centers plus Swiss-type turning cells, mill-turn centers, EDM, and wire cutting.

Tolerance and surface capability. Standard precision machining holds ±0.005mm linear tolerance, ±0.05° angular tolerance, and Ra 0.4 μm surface roughness on finishing passes. For ultra-precision features — bearing seats, sensor mounting bores, optical alignment surfaces — controlled-environment machining with thermal compensation reaches ±0.003mm. Every machined part ships with a CMM inspection report and material certification as standard.

Materials. We machine 50+ metals and engineering plastics, including 6061/7075 aluminum, 303/304/316/17-4PH stainless steel, Grade 5 titanium, Inconel 718, brass, copper, PEEK, and Ultem. The 5-axis capability is particularly relevant for impellers, turbocharger compressor wheels, medical implant geometries, and aerospace structural housings where tool access requires multi-directional simultaneous cutting.

Where it fits. When tolerance is ±0.005mm and the geometry is complex, 5-axis CNC machining services from China offer a cost-effective path from prototype to production. As a precision metal parts manufacturer with IATF 16949 process control, we maintain Cpk above 1.33 on critical features across production runs. Prototype parts ship in 3–5 days; production runs of 10,000+ units run on dedicated cells with tool-life monitoring and automated in-process gauging.

Aluminum Extrusion

Aluminum extrusion forces a heated billet through a custom steel die to produce continuous profiles with complex cross-sections — from simple angles and tubes to intricate multi-cavity heatsinks and structural frames. As an aluminum extrusion manufacturer, we work with the 6000-series alloy family that covers the majority of industrial and architectural applications.

Alloys and tempers. 6063-T5/T6 is the workhorse for architectural profiles, enclosure frames, and heatsinks — offering excellent surface finish, corrosion resistance, and formability. 6061-T6 delivers higher structural strength for truck bodies, rails, and load-bearing frames. 6082 and 6005 serve demanding structural applications, while 7075 is available for aerospace-grade extrusions.

One-stop extrusion. A custom 6063 aluminum extrusion project typically involves die design and fabrication, extrusion, surface treatment (anodizing, powder coating, electrophoresis, wood grain, or PVDF), precision cutting, CNC drilling and tapping, and assembly preparation. Consolidating these steps under one roof means your extrusion arrives ready to install — not as raw profile that still needs three more vendors before it becomes a part. Extrusion dimensional tolerance holds at ±0.05mm standard; CNC post-machining on critical features brings that to ±0.005mm.

Where it fits. Heat sinks for power electronics, LED lighting housings, solar panel frames, automated equipment structural framing, and EV battery tray components — all benefit from extrusion's combination of design freedom, thermal conductivity, and lightweight strength.

Forging

Forging shapes heated metal billets under compressive force within custom dies, producing components with continuous grain flow and superior mechanical properties compared to cast or machined equivalents. The internal grain structure follows the part's contour, which means forged parts carry higher impact toughness, fatigue resistance, and strength-to-weight ratios.

Closed die vs. open die. Closed die forging (also called impression-die forging) presses heated stock between two die halves to form near-net-shape parts from 0.3 kg to 100 kg. It is the process of choice for automotive connecting rods, control arms, gears, shafts, and transmission yokes — parts where failure is not an option. Open die forging compresses metal between flat or simple-contour dies, suited for large shafts, rings, and blocks above 100 kg where near-net shape is less critical.

Materials. We forge carbon steel (AISI 1020–1045), alloy steel (4140, 4130, 4340), stainless steel (304, 316), aluminum alloys, and copper alloys. Closed die forging achieves IT12–IT14 tolerance grades, refinable to ±0.01mm on critical features through post-forging CNC machining. Press capacity spans 315T to 4,000T with medium-frequency induction heating controlling billet temperature to ±10°C.

Where it fits. Closed die forging for automotive and aerospace produces suspension links, steering knuckles, aerospace structural fittings, and energy sector components for wind turbines and oilfield equipment — applications where forged grain flow integrity directly translates to safety and longevity.

Copper & Brass Castings

Sand casting and investment casting of high-conductivity copper and bronze alloys for electrical, thermal, and corrosion-resistant applications. Copper castings serve where electrical conductivity, thermal dissipation, or marine corrosion resistance are the primary design drivers.

Materials and capabilities. We cast C11000 (pure copper, ≥85% IACS conductivity), C36000 (free-cutting brass), and C86300 (manganese bronze) via sand casting for larger parts and investment casting for precision components. Typical applications include electrical connectors, bus bars, heat sinks, pump components, valve bodies, and marine hardware.

IATF 16949:2016. This automotive quality management standard requires documented process control, risk-based thinking (PFMEA), and continuous improvement across the entire supply chain. For automotive Tier-1 programs, we deliver complete PPAP Level 3 packages: Process Flow Diagrams, Control Plans, PFMEA, MSA studies, SPC data, dimensional results from CMM, material certificates, and capability studies (Cpk/Ppk). Every automotive part is traceable from raw ingot lot number through each manufacturing operation to final inspection, with batch parameter retrieval available in under 10 minutes via laser-marked QR codes.

ISO 9001:2015. This baseline quality management system governs non-automotive programs — industrial automation, consumer electronics, medical devices, and aerospace sub-tier supply. The same process control discipline, document control, and corrective action framework applies regardless of your industry.

In-house inspection capabilities:

• CMM (coordinate measuring machines) for dimensional verification of complex geometries, including GD&T features like coaxiality, flatness, and true position on machined sealing surfaces
• OES spectrometer for raw material chemical composition verification — every incoming ingot lot is verified against ASTM or GB standards before casting
• X-ray inspection for internal porosity and defect detection in safety-critical die castings
• Air-decay leak testing up to 20 bar for fluid system components
• Hardness and tensile testing for mechanical property verification on forged and heat-treated parts
• Surface roughness measurement for Ra verification on machined and as-cast surfaces

Every shipment includes a dimensional inspection report and material certification. For programs requiring it, we also provide IMDS registration, RoHS and REACH compliance documentation, and SGS/BV assay certificates.