Walk through any CNC machining factory, and you will always see the lathes spinning. CNC Turning is not niche process. It is the backbone of mass production run. Rings, adapters, bushings, nuts, fittings, nozzles- all of its comes from a turning center.
If you are an OEM buyer looking for CNC turning parts services in the USA and Europe, you need more than just a supplier. You need a factory that understands part function, geometry, machine capability, and how to scale production without losing accuracy.
This blog guide covers the types of parts made with CNC turning process. What makes them machinable, and how real factories keep tolerances tight. Even across mass production batches.
What Is CNC Turning?
CNC turning is a subtractive machining process where a round work piece rotates while a cutting tool removes material. It is a tool that makes cylindrical shapes. and aligned features, such as grooves, threads, and holes.
The majority of turning is performed on 2-axis lathes, athough factories also might use 3-axis and live tooling to complete turning as well as milling on the same setup.
In our Factory, we run:
- CNC Lathes with bar feeders for mass production.
- Swiss type machines for precision parts.
- VMC with trunnion for hybrid turning and milling parts.
Types of Parts You Can Create with CNC Turning
CNC turning is ideal for equal shape parts that rotate along a central axis. Most parts are designed with OD, ID, and face features.
Shafts and Axles
- Used in motors, pumps, drives
- Tolerances often around ±0.01 mm
- May include key slots and threads
Bushings and Spacers
- Act as sleeves and gaps between components
- Chamfered edges, smooth bores
- Often finished with hard anodizing film
Threaded Fasteners
- Custom bolts, screws, and studs
- Cut with single-point threading and thread rolling
- Class 2A/2B & 6g/6H tolerance threads
Housings and Sleeves
- Thicker-wall turned parts
- May include snap ring grooves, steps, and flange faces
- Sometimes combined with VMC work
End Caps and Covers
- Press-fit and threaded closures
- Usually anodized and polished
- Requires good surface finish on face and OD
Nozzles and Fittings
- Complex ID tapers and sealing grooves
- Cut in one setup to avoid concentricity error
Pins and Dowels
- Simple parts, but critical tolerance
- OD must be perfect, usually ±0.05 mm
Types of CNC Turning Operations
There is no one size fits all turning cut. Each feature needs a different approach. Our shop regularly runs these CNC turning operations
- Facing - Cleans up the raw face to make it square. Always the first step.
- OD Turning - Cuts the outside diameter to final size, often with rough and finish passes.
- Grooving - Adds O-ring grooves. We use profile inserts for clean corners.
- Parting Off - Separates the part from bar stock. Requires careful control to avoid burrs.
- Threading - Metric and inch threads, either cut or rolled. Thread pitch and depth controlled by CAM.
- Drilling and Boring - For center holes, and bores. Depth held to ±0.1 mm or better.
- Knurling – Adds a grippy pattern. Mostly for press-fit zones.
CNC Turning vs Milling Process - What to Use and When
We get this question regularly, Should the part be turned or milled?
Its depends on the part shape. If it rotates along a central axis, turning process us best suits, but parts block types then milling works better..
| Feature | CNC Turning | CNC Milling |
|---|---|---|
| Best for | Round, cylindrical parts | Flat, angular, and block type parts |
| Tool path | Fixed tool and spinning part | Spinning tool, fixed part |
| Thread quality | Higher accuracy | Less consistent without tapping head |
| Tolerances | Very tight on concentricity | Strong on flatness and hole location |
| Cycle time | Shorter for symmetrical parts | Better for detailed geometry |
We often combine both. A turned housing might go to the VMC to get drilled holes flats.
Professional Tips for Designing Turned Parts
Here is our best suggestion:
- Use standard diameters - 10 mm, 20 mm, 25 mm, easier to match stock and tools.
- Avoid deep internal grooves - Tool access gets tricky, inserts chatter.
- Tapered bores - Include angle call outs & 2D section views.
- Threads - Call out full thread depth. Avoid blind holes under M4 if possible.
- Wall thickness - For aluminum, keep >1.5 mm wall to avoid deflection.
And always send 2D + 3D files together if you can. It saves time.
CNC Turning Surface Finish Comparison
The insert, RPM, feed, and material all affect the finish. Depending on the function, we run various finish levels.
| Surface Finish Type | Roughness (Ra) | Use Case |
|---|---|---|
| Standard as-turned | 1.6 – 3.2 micron | Internal parts, sleeves, basic fits |
| Fine-turned | 0.8 – 1.6 micron | Sealing faces, polished caps |
| Post-polished | < 0.4 micron | Cosmetic parts, visible assemblies |
| Anodized (after turning) | Depends on prep | Cosmetic + corrosion protection |
We verify finish with surface roughness testers (Ra gauges) on critical zones.
Materials Commonly Used in CNC Turning
CNC turning process supports a wide range of metals, but material you have to choose according to purpose and application, and end-use environment.
Here are the materials we work with and how they actually behave in the machine:
Brass
Easy to machine and almost no burr. Perfect for threaded fittings and undercuts needed in parts. Also, the most stable metal for a long production run.
Aluminum (6061, 6063, 7075 Grade)
Lightweight, cheap, but it reacts differently batch to batch. Great for parts where weight matters.
Stainless Steel (304, 316 Grade)
Hard material and slow for machining. We always watch chips load and use through coolant drills to stop overheating.
Mild Steel
Cheaper material but needs post-plating or coating. The thread is cut clean, but it rusts fast.
Copper
Copper is very sticky. We always keep backup inserts ready. But very good when conductivity matters.
Our team adjusts feeds, speeds, and inserts depending on the grade, job size, and tolerance. Even small shifts between 6061 and 7075 show up on finish and tool life.
Aluminum vs Brass vs Steel in Turned Parts
Each material machines differently. Picking the right one depends on the part’s use.
| Property | Aluminum | Brass | Steel |
|---|---|---|---|
| Machinability | Excellent | Smooth | Hard |
| Weight | Light | Medium | Heavy |
| Corrosion Resistance | Anodizable | Natural | Stainless grades only |
| Cost per part | Low (mass volume) | Medium | Higher (tooling) |
| Best Use | EV parts, housings, drone | Fittings, connectors, knobs | Shafts, bushings, load parts |
We keep certified stock of all three, with RoHS support.
Finishing Capability in CNC Turning
Not every part leaves machine ready to ship. Some need cosmetic finished. Others need protection from corrosion. We offer post-machining surface treatments based on material, spec, and function.
Threads are often masked and post-tapped depending on the coating process.
As-machined finish
No coating just clean machined finish. We deburr all edges and solvent-clean before packing.
Anodizing
Clear or black anodize type 2. Type 3 hard anodizing available for wear parts. Works best on 6061 and 7075 aluminum grade.
Chem Film
ROHS compliant yellow and clear coating. Mostly used on aerospace and electrical parts for conductivity.
Electroplating
Nickel for wear resistance, zinc for corrosion protection.
Industries That Use CNC Turned Parts
- Medical devices
- EV & automotive
- Aerospace
- Industrial automation
- Electronics
- Plumbing and HVAC
We often bundle different turned parts into one shipment, labeled by PO and part code.
Get CNC Turning Parts
If you need custom OEM cnc turnings parts, shafts, bushings,
spacers, housings, and adapters in the USA or Europe and built by real operators, then these are your companies.
Request a Free CNC Turning Parts Quote now.