CNC Turned Parts — Precision Turning of Stainless Steel, Brass, Aluminum & More
Quick Answer
CNC turned parts are rotationally symmetric components produced on a CNC lathe by removing material from a spinning bar or blank. Emitech manufactures precision turned parts in stainless steel (303, 304, 316L), brass, aluminum, carbon/alloy steel, titanium, and engineering plastics on 30+ CNC lathes with 2-axis to 5-axis live tooling. Standard turning tolerance is ±0.03 mm, with critical features held to ±0.01 mm, and parts can be turned up to Ø 250 mm × 400 mm.
Whether you need CNC prototypes, custom CNC parts, or production volumes above 10,000 pieces, upload your drawing to request a 24-hour CNC turned parts quote with DFM feedback.
What Are CNC Turned Parts
CNC turned parts are components created by mounting a cylindrical bar or blank in a chuck and feeding a stationary cutting tool into the rotating workpiece. The process is ideal for parts with rotational symmetry such as shafts, pins, bushings, spacers, connectors, fittings, and fasteners. Because the workpiece spins rather than the tool, CNC turning delivers excellent concentricity, surface finish, and repeatability for round features.
Compared to CNC milling, turning is usually faster and more cost-effective for long or round parts. Milling is preferred for prismatic parts with flat faces, pockets, and complex 3D contours. Many projects combine both: turned blanks are moved to a mill for flats, holes, or slots, while MIM near-net blanks are finished with turning for critical bores and threads.
Emitech's CNC turning department supports single-piece prototypes through 200,000+ pieces per month, with live tooling that completes cross-drilling, tapping, and milling without a second setup. This reduces handling time, improves accuracy, and keeps lead times short.
CNC Turned Parts by Material
Stainless Steel Turned Parts
Stainless steel turned parts are the most requested category at Emitech. Grades 303, 304, and 316L offer a balanced combination of corrosion resistance, machinability, and mechanical strength. 303 is free-machining and ideal for fasteners and fittings; 304 is the workhorse for general corrosion resistance; 316L adds molybdenum for marine, chemical, and medical environments. As-turned surface finish is typically Ra 0.8–1.6 µm, and parts can be passivated or electropolished for enhanced corrosion performance.
Brass CNC Turned Parts
Brass C36000 is prized for excellent machinability, electrical conductivity, and an attractive gold-like finish. Brass turned parts are common in electrical connectors, valve bodies, pneumatic fittings, decorative hardware, and instrument components. The material chips cleanly, allowing fast cycle times and tight tolerances on small diameters.
Aluminum Turned Parts
Aluminum 6061-T6 and 7075 are lightweight, fast to machine, and cost-effective for prototypes and small batches. 6061 is widely used for brackets, spacers, and general hardware; 7075 is selected when higher strength is required. Aluminum turned parts are often anodized for hardness, color, and corrosion protection, making them popular in electronics, aerospace, and robotics.
Steel Turned Parts
Carbon and alloy steel grades such as 12L14, 1045, 4140, and 4340 deliver higher strength, hardness, and wear resistance than aluminum or brass. These materials are chosen for shafts, gears, pins, tool holders, and industrial fasteners. After turning, parts can be heat treated, case hardened, or ground to meet demanding mechanical requirements.
Plastic Turned Parts
Engineering plastics such as POM, PEEK, PTFE, and Nylon are turned for insulating, low-friction, and chemically resistant components. Plastic turned parts are lighter than metal, do not corrode, and are ideal for bushings, bearings, seals, and electronic insulators. PEEK is used for high-temperature and medical applications, while POM offers excellent dimensional stability and machinability.
| Material | Common Grades | Typical Turned Parts | Applications |
|---|---|---|---|
| Stainless steel | 303, 304, 316L, 17-4PH | Shafts, pins, bushings, fittings, fasteners | Medical, marine, food, chemical |
| Brass | C36000, C46400 | Connectors, valves, nozzles, terminals | Electrical, plumbing, instrumentation |
| Aluminum | 6061-T6, 7075, 2024 | Spacers, standoffs, knobs, housings | Aerospace, electronics, robotics |
| Steel | 12L14, 4140, 4340, 8620 | Gear blanks, shafts, pins, tool holders | Automotive, industrial, tooling |
| Plastic | POM, PEEK, PTFE, Nylon | Bushings, bearings, seals, insulators | Medical, electronics, chemical |
Precision Turning Capabilities
- Equipment: 30+ CNC lathes including 2-axis, 3-axis, 4-axis, and 5-axis machines with live tooling
- Maximum turning size: Ø 250 mm × 400 mm length
- Standard tolerance: ±0.03 mm
- Precise tolerance: ±0.01 mm on critical diameters and bores
- Surface finish: Ra 0.8–3.2 µm as-turned; finer finishes available with grinding or polishing
- Live tooling: Cross-drilling, tapping, slotting, and milling performed without removing the part from the chuck
- Monthly capacity: 200,000+ turned pieces
CNC Turned Parts vs CNC Milled Parts
| Factor | CNC Turning | CNC Milling |
|---|---|---|
| Ideal geometry | Round, cylindrical, rotational parts | Prismatic, flat, multi-sided parts |
| Speed | Faster for shafts, pins, and bushings | Faster for pockets, slots, and complex faces |
| Concentricity | Excellent, because the part rotates on one axis | Good, but may require multiple setups |
| Surface finish | Fine on OD and ID surfaces | Fine on milled faces |
| Best volume | 10 to 100,000+ pieces | 1 to 10,000+ pieces |
Secondary Operations for Turned Parts
Emitech completes most secondary operations in-house so parts arrive ready for assembly.
- Heat treatment: Hardening, tempering, annealing, and case hardening for steel grades
- Surface finishing: Anodizing, passivation, electroless nickel plating, zinc plating, chrome plating, PVD, and polishing
- Grinding: Cylindrical and centerless grinding for tolerances tighter than ±0.01 mm
- Knurling: Diamond, straight, and spiral knurl patterns for grip and press fits
- Threading: External and internal threads cut or rolled to UN, metric, and custom standards
- Marking: Laser marking and dot peen for part numbers, logos, and traceability
Industry Applications
Automotive
CNC turned parts for automotive include sensor housings, shafts, bushings, valve stems, and fasteners. Emitech supports ISO 9001:2015 quality documentation with full traceability for safety-critical components.
Medical Devices
Surgical handles, orthopedic pins, dental components, and instrument connectors are turned from 303, 304, and 316L stainless steel or titanium. Passivation and electropolishing meet biocompatibility and cleanability requirements.
Electronics
Standoffs, spacers, terminals, connectors, and heat-dissipating ferrules are turned from aluminum, brass, and stainless steel. Small diameters and tight tolerances are routine for electronics assemblies.
Aerospace
Titanium and aluminum fasteners, bushings, and alignment pins are turned to aerospace tolerances. Emitech can provide comprehensive first-article inspection reports and material certifications.
Industrial Equipment
Hydraulic fittings, valve stems, pump shafts, and gear blanks are turned from steel, brass, and stainless steel for industrial machinery, fluid power, and process equipment.
Request a Quote for CNC Turned Parts
To receive a fast and accurate quotation for your CNC turned parts, send us the following information. Our engineering team will review your design for manufacturability and respond within 24 hours.
- 3D model: STEP, IGES, or native SolidWorks file
- 2D drawing or PDF: tolerances, critical dimensions, and thread specifications
- Material grade: e.g., 316L stainless steel, C360 brass, 6061-T6 aluminum, 4140 steel, POM
- Surface finish: as-machined, anodized, passivated, plated, polished, etc.
- Quantity: prototype quantity and estimated annual volume
- Delivery target: required sample date and production lead time
Email: yaoqingpu1983@gmail.com
WhatsApp: +86 138 1403 4409
Frequently Asked Questions
Q: What materials can be CNC turned?
Emitech turns stainless steel (303, 304, 316L, 17-4PH), brass (C360), aluminum (6061, 7075), carbon and alloy steel (12L14, 4140, 4340, 8620), titanium, and engineering plastics (POM, PEEK, PTFE, Nylon).
Q: What is the difference between CNC turning and CNC milling?
CNC turning rotates the workpiece against a fixed cutting tool and is best for round, cylindrical parts. CNC milling rotates the cutting tool against a fixed workpiece and is best for flat, prismatic, or complex multi-sided parts.
Q: What tolerances can CNC turned parts achieve?
Standard turned tolerance is ±0.03 mm. Critical diameters and bores can be held to ±0.01 mm with precise tooling, stable fixturing, and CMM verification.
Q: What is the minimum order quantity for CNC turned parts?
There is no MOQ. Emitech accepts one-piece prototypes and scales to production runs of 10,000 pieces or more.
Q: Can you turn plastic parts?
Yes. POM, PEEK, PTFE, and Nylon are commonly turned for bushings, bearings, seals, and insulators. Plastics require sharp tooling and controlled feeds to avoid melting or chipping.
Q: What is the typical lead time for turned parts?
Prototypes ship in 3–7 business days. Production lead time is 2–4 weeks depending on quantity, material, and secondary operations.
Q: Do you offer surface finishing for turned parts?
Yes. Common finishes include anodizing, passivation, plating, polishing, PVD, bead blasting, and grinding. Surface treatment typically adds 2–5 days.
Q: How do I get a quote for CNC turned parts?
Send a STEP or IGES model plus a 2D drawing with tolerances, material, quantity, and finish requirements. Emitech provides DFM feedback and a detailed quote within 24 hours.
Source Custom MIM Parts from Emitech
Nanjing Emitech (ISO 9001:2015) delivers MIM from tooling through sintering and finishing, plus precision CNC machining for prototypes and secondary operations. Custom MIM parts · CNC machining services · MIM services · Request a quote