Online Custom CNC Machining Services

CNC Machining Services — Precision Milling, Turning & 5-Axis

Emitech provides CNC machining services from our ISO 9001:2015 certified facility in Nanjing, China. We combine CNC milling, CNC turning, and 5-axis machining with in-house quality control for automotive, medical, aerospace, and industrial OEMs. From single prototypes to production batches of 10,000+, every part is programmed, cut, and inspected by the same engineering team.

What Is CNC Machining?

CNC machining (Computer Numerical Control machining) is a manufacturing process where pre-programmed software controls the movement of factory tools and machinery. Unlike manual machining, CNC allows precise, repeatable cutting of complex 3D shapes from solid blocks of metal or plastic. The process is subtractive — material is removed from a workpiece until the final geometry is achieved.

CNC machining is the go-to manufacturing method when you need:

• Prototypes quickly — no tooling required, parts ship in days
• Tight tolerances — down to ±0.01 mm for precision fits
• Low-to-medium volumes — 1 to 10,000+ pieces without mold investment
• Wide material choice — aluminum, stainless steel, brass, copper, titanium, engineering plastics
• Excellent surface finish — as-machined Ra 0.8–3.2 µm, with polishing and coating options

The most common types of CNC machining are CNC milling (rotating tool cuts a stationary workpiece — best for pockets, slots, and contoured surfaces) and CNC turning (workpiece rotates against a stationary tool — best for cylindrical parts like shafts and bushings). 5-axis machining combines both approaches for complex geometries in a single setup.

Why Choose CNC Machining from China?

China is the world's largest CNC machining market, and for good reason. A CNC machining factory in China like Emitech offers:

• Cost advantage: Labor and overhead rates are 40–60% lower than comparable shops in North America or Europe, while equipment quality is identical (Haas, DMG Mori, Mazak).
• Scale: Chinese CNC shops routinely operate 50+ machines under one roof, so production volumes that would strain a regional shop are standard.
• Integrated supply chain: Raw materials, heat treatment, anodizing, plating, and assembly are all available within the same industrial zone, reducing logistics time and cost.
• One-stop manufacturing: Emitech adds MIM to CNC — you can get net-shape MIM parts with precision CNC finishing from a single supplier, eliminating the cost and delay of coordinating two vendors.

Our Nanjing location — 300 km from Shanghai port — means fast ocean and air freight to North America, Europe, and Asia-Pacific. Standard shipping times are 7–21 days by sea and 3–5 days by air. See our CNC machining China page for more details on logistics, quality standards, and export documentation.

Capabilities at a Glance

Our CNC department is organized around four core service lines. Each line can run independently or as a secondary operation after MIM sintering, giving engineers a single source for complex metal components. Whether you need a one-off prototype for design validation or a recurring production batch, the same team programs the toolpaths, selects the workholding, and inspects the result, so quality is consistent from first article to full release.

Precision CNC machined part produced at Emitech's Nanjing facility

Why Emitech for CNC Machining

Engineers and purchasing managers choose Emitech because we combine speed, quality discipline, and process integration. We do not treat CNC as a standalone commodity; we treat it as one option in a broader manufacturing strategy that also includes MIM, surface treatment, and inspection. That perspective helps us recommend the right route for each part instead of forcing every geometry into the same machine.

Related CNC services: CNC machining capabilities for a full equipment overview, CNC turning services for shafts and rotational parts, precision machining services for tight tolerances, CNC prototyping for fast validation, custom CNC machined parts for OEM components, and CNC machining manufacturer in China for sourcing and export support.

Equipment & Capacity

Emitech's machining floor in Nanjing is equipped with a balanced mix of high-speed mills, CNC lathes, and support equipment. The shop is laid out for prototype-to-production workflows, so a single part can be proven on a 3-axis mill and then scaled to multi-axis production cells without re-sourcing. Preventive maintenance is scheduled weekly to keep spindle runout, positioning accuracy, and repeatability within specification, and tooling is tracked by job to minimize setup errors.

Each job begins with a CAM review in which our programmers select cutters, feeds, speeds, and workholding based on material and feature geometry. A digital tooling library ensures that repeat orders use the same tool offsets and fixture configurations, which shortens setup time and reduces variation between lots. For jobs that combine machined and MIM features, the CNC program is shared with the MIM engineering team so secondary datum references remain consistent.

• CNC turning lathes: 30+ units with two-, three-, and five-axis configurations and live tooling.
• CNC milling centers: 3-axis, 4-axis, and simultaneous 5-axis vertical machining centers.
• Maximum milling travel: 800 × 500 × 400 mm.
• Maximum turning diameter: 250 mm with bar feeder and chuck options.
• Support equipment: wire EDM, surface grinding, tapping, and deburring stations.
• Capacity range: 1-piece prototypes to 10,000+ piece production runs per release.

CNC machining workshop at Emitech's Nanjing facility

Tolerances & Part Size

Our standard tolerances follow ISO 2768-m for machined metal parts and ISO 2768-c for plastics. Tighter tolerances are quoted as special characteristics and inspected with CMM or digital measuring equipment. For design-stage guidance, refer to our DFM guidelines. When a drawing calls out GD&T such as true position, profile of a surface, or perpendicularity, our programmers build inspection points into the process so those features are checked before the part moves to finishing.

Materials

We machine a broad range of metals and engineering plastics. Material selection affects machinability, tolerances, surface finish, and unit cost, so our engineers help match the alloy to the application rather than defaulting to the easiest option. Factors such as corrosion exposure, operating temperature, strength-to-weight ratio, and cosmetic requirements all influence the recommendation. We stock common aluminum, stainless, and carbon steel grades for fast turnaround, while specialty alloys and plastics are sourced against confirmed orders.

For demanding stainless applications, our guide to 17-4 PH stainless steel explains how heat treatment affects hardness and corrosion resistance. For shafts and high-strength components, see our 4140 steel properties and applications guide. Titanium projects can draw on both our CNC capability and the titanium MIM guide. If you are comparing aluminum MIM against machined aluminum, our article on MIM for aluminum explains when CNC remains the better choice.

When selecting a material, we also consider chip formation, work-hardening tendency, and the need for post-machining heat treatment. Free-machining grades such as 12L14 and 303 reduce cycle time, while tougher alloys like titanium or Inconel require slower speeds and specialized tooling. Sharing the end-use environment—temperature, load, and exposure to chemicals—helps us recommend the grade that balances performance with manufacturability.

CNC milling parts in aluminum and stainless steel

Surface Finishes

Surface finish is rarely an afterthought at Emitech. We match the process to the functional or cosmetic requirement and coordinate finishing with machining so that critical dimensions remain in tolerance after treatment. Anodizing, for example, adds a measurable oxide layer, so bores and threads are machined undersize where needed. Plating and polishing remove stock, so those steps are sequenced before final inspection rather than after.

• As machined: Tool marks visible; Ra 0.8 – 3.2 μm depending on tool path and material.
• Bead blasting: Uniform matte finish that hides minor tool marks and improves coating adhesion.
• Anodizing (Type II & Type III): Hard, corrosion-resistant oxide layer for aluminum; available in clear or dyed colors.
• Passivation: Restores corrosion resistance on stainless steel after machining.
• Electroless nickel / chrome plating: Wear and corrosion protection for steel and copper alloys.
• Polishing: Mirror or satin finishes for decorative or low-friction surfaces.

Our MIM parts surface treatment page covers many of the same processes used after CNC, and our blog post on surface finish after machining compares Ra values and cost drivers.

CNC machined parts ready for polishing and surface finishing

Industries We Serve

CNC machining supports the same OEM markets we serve with MIM, but it is usually selected when part geometry is simpler, tolerances are tighter, or volumes do not justify hard tooling. The following industries rely on Emitech for machined prototypes and production parts. In each market, we align material selection, finishing, and inspection to the relevant regulatory or performance expectations.

Case Studies

The following representative projects illustrate how Emitech combines CNC machining with material knowledge and inspection discipline to solve real engineering problems. Customer names and product lines are anonymized. Both projects moved from first article through recurring production, demonstrating the repeatability our process controls are designed to deliver.

Precision gear and rotational components manufactured by CNC machining

MIM + CNC Together

Combining MIM and CNC machining lets engineers capture the best of both processes: MIM delivers complex near-net geometries in high volumes at low per-part cost, while CNC provides the tight tolerances, threads, and surface finishes that sintering alone cannot guarantee. At Emitech, parts move directly from our sintering line to CNC secondary operations without leaving the factory. This integration is especially valuable when a component has intricate external geometry but also requires precision bores, flat faces, or threads.

Typical MIM-to-CNC workflows include reaming holes to ±0.01 mm, machining mating faces to flatness specifications, cutting threads, and adding cosmetic surfaces. The decision between starting from bar stock or from a MIM blank depends on annual volume, geometry complexity, and material. Our MIM vs CNC comparison explains the break-even economics, and our MIM CNC secondary operations page details the handoff process. For joining MIM blanks after machining, our guide on can you weld MIM parts covers weldability and post-weld finishing considerations.

In practice, the MIM-plus-CNC route becomes cost competitive when annual volumes exceed a few thousand pieces and the geometry would require many machining setups if cut from solid. At lower volumes, machining from bar stock is usually faster and more economical, which is why our small-batch MIM pricing guide is a useful reference for early-stage comparisons.

CNC turned part ready for integration with MIM secondary operations

Frequently Asked Questions

Request a CNC Machining Quote

Whether you need a single prototype or a recurring production batch, Emitech delivers CNC machining services with ISO 9001 quality control and one-business-day quoting. Upload your drawing or 3D model and receive a detailed quotation with DFM feedback.