01
Tolerance drifts mid-run
Free-cutting brass cuts clean on the first 20 pieces, then thermal growth and tool wear push diameters past the limit. If your shop only checks the first article, the drift shows up in your assembly station weeks later.
Brass Turning & Milling
CNC Brass Machining Turned Parts
We turn and mill brass parts to ±0.005 mm on 127 CNC machines, from a single prototype to 10,000+ pieces. Upload a STEP file and get a quote with DFM notes in 12 hours.
C36000 / C27400 / C28000±0.005 mmØ400 mm rotary tableNo minimum order quantityISO 9001:20153–5 day shipping
16Simultaneous 5-axis centers
±0.005 mmAchievable tolerance
3–5 daysTypical parts shipping
99.99%Qualification rate
Where brass parts go wrong
Four problems we see on turned brass parts
Most of these show up after the first article, not on the drawing.
02
Chatter on thin-wall sleeves
A tube with a 1 mm wall and a 40 mm bore will ring on a standard three-jaw chuck. The result is ovality and a surface that will not seal. This is a workholding decision, not a spindle speed decision.
03
Burrs nobody quoted for
Cross holes on a turned shaft leave an internal burr that a tumbling pass will not reach. Your team ends up hand-deburring 500 pieces at the bench, and the labor never appeared in the original price.
04
Plating changes the fit
Electroless nickel adds 5–25 μm per surface. A pin that gauges fine before plating can bind afterwards. If the finish was chosen after the drawing was released, the tolerance stack no longer closes.
How we run brass
Turning and milling in one setup
Two capabilities that decide whether a brass part stays in tolerance.
Mill-turn
One chucking instead of three
Sixteen mill-turn centers carry the part through turning, cross drilling and milling without releasing it. For a valve body with ports on four faces, that removes the position error you get from re-chucking on a three-axis lathe.
Brass is soft and gummy at high surface speed. We cut C36000 at parameters tuned to the alloy and use high-pressure coolant so chips clear the bore instead of welding to the tool.
- 116 mill-turn centersTurn, drill and mill in a single setup
- 2Ø400 mm rotary tableIndexed features on round parts
- 3±0.005 mmHeld across the full run, not just the first piece
Workholding & inspection
Soft jaws and in-process gauging
Thin-wall brass sleeves need bored soft jaws that match the finished diameter, plus light radial clamping. Done that way, a 1 mm wall holds round within tolerance and the bore finishes at Ra 0.8–1.6 μm without a second op.
Every part is checked before shipment, with raw material verification, in-process monitoring and a final inspection. Dimensional reports and material certs come with the shipment when you ask for them.
- 1100% inspectionFinal check on every part before it ships
- 2Reports on requestDimensional data and material certificates
- 3Ra 0.2–0.8 μmAvailable on sealing and bearing surfaces
Material selection
Which brass alloy for which part
Pick the alloy before you pick the tolerance.
| Alloy | Typical part | Why this one |
|---|---|---|
| C36000 | Fittings, valve bodies, connectors | Free-cutting, best machinability, not for bending |
| C27400 | Pins, terminals, fasteners | Cold-formable, good strength, slightly harder to cut |
| C28000 | Pipes, hardware, marine fittings | Corrosion resistant, dezincification risk in seawater |
| C101 / C110 | Busbars, RF shields, contacts | High conductivity, gummy to turn, needs sharp tools |
What we make
Brass turning services and adjacent work
One shop for the turned part and everything bolted to it.
01
CNC Turning & Milling
Mill-turn centers handle shafts, fittings, valve bodies and connectors in one setup, with cross holes and milled flats included.
02
5 Axis CNC Machining
Sixteen simultaneous 5-axis centers cut contoured ports and angled faces that would need three fixtures on a lathe.
03
Rapid Prototyping
One-off brass prototypes to check fit and function before you commit to a production run. No minimum order quantity.
04
Surface Finishing
Electroless nickel, zinc, silver and gold plating, plus bead blasting, brushing and polishing. Laser marking down to 1.5 mm character height.
05
Assembly & Hardware
Press fits, threaded inserts and sub-assembly of turned brass parts with the mating components from the same drawing set.
06
Sheet Metal & Casting
Brackets, housings and die-cast enclosures when a brass part sits inside a larger assembly. One supplier, one inspection chain.
Scope
Turning capacity at a glance
What fits on the machines and what comes with the shipment.
| Item | Range |
|---|---|
| Maximum part size | 4,000 mm |
| Lathe travel | 4,000 × 400 × 150 mm |
| Milled travel | 750 × 1,150 × 550 mm |
| Rotary table | Ø400 mm |
| Tolerance | ±0.005 mm |
| Finish | Ra 0.2–0.8 μm to Ra 1.6–3.2 μm |
| Order size | One prototype to 10,000+ parts |
| Shipping | 3–5 days after production start |
Why GreatLight
Six numbers that decide the job
We are a 15-year turning shop in Dongguan, not a trading office.
15Y
Machining since 2011
Fifteen years on turned brass and stainless work, with three wholly-owned plants and 150 technicians.
127
CNC machines
Sixteen simultaneous 5-axis centers, 16 mill-turn centers, 12 four-axis mills and 27 three-axis machines.
12h
Quote and DFM
Quotation with a free DFM analysis inside 12 hours of receiving a usable STEP or DXF file.
24h
Production start
After drawing release and material confirmation, cutting can begin within 24 hours.
7,600 m²
Floor space
Turning, milling, finishing and inspection under one roof in Dongguan, plus a plant in Singapore.
<2%
Late-delivery risk
Historical late-delivery probability across shipped orders. Plans are built from machine hours, not hope.
99.99%Qualification rate
100%Inspection before shipment
4ISO certifications held
No MOQOne piece to 10,000+
Industry fit
What these industries need from brass parts
Automotive & EV
Terminals and busbars need tight bore alignment and no burrs on the mating face. Plating thickness is controlled against the drawing so press fits still close.
- ±0.005 mm
- IATF 16949:2016
Electronics & RF
Connector shells and shields call for conductive alloys and clean edges. C101 and C110 are turned with sharp tooling to avoid smearing the surface.
- C101 / C110
- Ra 0.8–1.6 μm
Industrial Machinery
Valve bodies and manifolds combine turned bores with milled ports on several faces. Mill-turn keeps those features in one datum instead of three fixtures.
- 16 mill-turn centers
- Ø400 mm rotary table
FAQs
Questions engineers ask before ordering
Which brass alloy should I specify?
C36000 is the default when the part is mostly turned and you want the best machinability. It contains lead and is not suitable for bending or heavy forming.
If the part is cold-formed, threaded hard or used near seawater, C27400 or C28000 is the better choice. C28000 resists corrosion but can dezincify in salt water, so marine work often moves to a different alloy entirely.
Can you hold ±0.005 mm on a long brass shaft?
It depends on the length-to-diameter ratio. On a rigid part with a ratio under roughly 5:1, ±0.005 mm is routine.
Above that, deflection and thermal growth take over. We would either turn it between centers with a steady rest or split the operation, and we will tell you which one the drawing needs before quoting.
Does plating change the dimensions?
Yes. Electroless nickel adds roughly 5–25 μm per surface depending on the bath and dwell time.
For a press fit or a bore that takes a pin, tell us the finish up front so the pre-plate dimensions are set correctly. Otherwise the part gauges well before plating and binds after.
How do you deburr cross holes?
Cross holes drilled into a turned shaft leave a burr where the two bores meet. Tumbling alone will not remove it.
We deburr those intersections with a controlled cutter path or a back-chamfer tool during the cycle, then verify under magnification at final inspection.
What do you need for a quote?
A STEP or DXF file, the alloy, the surface finish, the quantity and any critical dimensions. A tolerance block on the drawing saves a round of questions.
Quotation and a free DFM analysis come back within 12 hours. Files are handled as confidential, and we can sign an NDA before you send anything.
What is the smallest order you accept?
There is no minimum order quantity. A single prototype and a 10,000-piece run go through the same process and the same inspection.
Setup cost is spread differently at one piece than at ten thousand, so the unit picture changes with volume. Ask for both and compare.
How fast can parts ship?
Production can start within 24 hours of drawing release and material confirmation. Typical turned brass parts ship in 3–5 days.
Lead time depends on material availability and finishing. Plating and anodizing add a separate step, so factor that in when you set your build date.
Which certifications do you hold?
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022.
The first three cover quality management for industrial, automotive and medical work. ISO 27001 covers how we handle your drawings and data.
Send a brass part and get a real number
Upload your STEP file and we will return a quotation with DFM notes, a tolerance review and a shipping window.
12-hour quote100% inspectionNo minimum order quantityNDA on request
