Brass CNC Turning Services
Free-cutting, leaded and naval brass turned to ±0.02mm for bushings, fittings, connectors, valve parts and instrument bodies. C360, C377, C464 and HPB machined from bar, with press-fit and plating-ready surfaces, from a single prototype to 10,000 pieces.
Free Consultation24h
Rapid Quote
1 pc
MOQ
±0.02mm
Dimensional Tolerance
Ra 0.8μm
Surface Roughness
Materials
| Grade | Properties | Typical Applications |
|---|---|---|
| C360 Free-Cutting Brass | Tensile strength 310 MPa, around 3% lead for fast cutting and chip breaking, machinability index around 90% of free-machining steel, good corrosion resistance in fresh water | Fittings, bushings, spacers, standoffs, threaded adapters, general hardware |
| C377 Lead-Free Brass (CW511L) | Tensile strength 400 MPa, 0.3% lead content for lead-free compliance in drinking water and food contact parts, good machinability with a slightly lower cutting speed than C360 | Sanitary fittings, valve bodies, potable water components, food equipment parts, EU RoHS projects |
| C464 Naval Brass | Tensile strength 415 MPa, 60% copper with 39% zinc and 1% tin, good corrosion resistance in seawater and higher strength than standard brass | Marine hardware, ship fittings, naval instrument parts, seawater manifolds |
| C48500 HPB Brass (70/30) | Tensile strength 300 MPa, 70% copper and 30% zinc, lead content around 0.25% for general non-potable use, excellent formability and corrosion resistance | Plumbing fittings, connectors, decorative parts, lamp components, general hardware |
| C260 Cartridge Brass | Tensile strength 390 MPa, 70% copper and 30% zinc, higher strength than HPB, good cold forming behaviour and takes a fine finish | Ammunition components, cartridge cases, precision hardware, instrument parts |
| CZ121 / CuZn37 Brass | Tensile strength 350 MPa, standard free-cutting brass with a good balance of strength, corrosion resistance and machinability | Automotive components, hardware, bushings, threaded inserts, general turned parts |
Process Parameters
| Parameter | Standard Range |
|---|---|
| Dimensional Tolerance (Critical Features) | ±0.02 mm, ±0.01 mm on request |
| General Tolerance (ISO 2768-m) | ±0.1 mm |
| As-Machined Surface Roughness | Ra 1.6 μm, Ra 0.8 μm finish pass |
| Part Size (CNC Turning) | up to Ø300 x 600 mm |
| Part Size (CNC Milling) | up to 600 x 400 x 300 mm |
| Bar Diameter | Ø2 to Ø250 mm |
| Thread Range | M2 to M40, UNC/UNF, BSP, NPT, G |
| Concentricity (Turned Parts) | 0.01 mm |
| Straightness (Bar Stock, 100 mm) | 0.05 mm |
| Minimum Wall Thickness | 0.4 mm |
Surface Finishes
As-Machined (Mill Finish)
Freshly turned surfaces keep a light machining film with visible tool marks, which is normal for functional parts. Where a part will be plated, the finish pass is planned so the coating sits on a consistent base with no residual burr at the shoulder.
Bead Blasting
Glass bead blasting at 60 to 120 mesh produces a uniform satin finish that removes turning marks and blends edges. The blasting media must be clean iron-free media, otherwise free iron particles cause rust blooms on brass during storage.
Polishing
Mechanical polishing reaches Ra 0.2 μm on sealing faces, bearing journals and visible trim. Brass polishes faster than steel because it is softer, so wheel pressure and rpm stay low to avoid rounding the shoulder and burning the surface.
Nickel Plating
Electroless nickel phosphorus 5 to 25 μm with hardness up to 500 HV after baking, chosen for wear resistance on shafts and for a uniform deposit inside bores and threads where electroplating throws unevenly.
Tin Plating
Tin or tin-nickel plating 5 to 15 μm for soldering surfaces, electrical contacts and food contact parts where a non-reactive, solderable layer is needed.
Chrome Plating (Trivalent)
Hard chrome or trivalent chrome 5 to 30 μm for wear surfaces, bearing areas and corrosion protection. The plating is applied after dimensional checks so the coating thickness is accounted for in the final tolerance.
Lacquering and Sealant
Clear lacquer, wax or corrosion inhibitor for parts stored long term or exposed to moisture. Latex and oil-free handling matters because fingerprints on brass accelerate tarnish and leave permanent marks on visible parts.
Design for Manufacturing (DFM)
- Specify the lead content explicitly, because C360 at around 3% lead and C377 at 0.3% lead are not interchangeable for potable water or food contact use
- Keep wall thickness at 0.8 mm or more on C360, since the free-cutting grade has less chip strength and thin sections deflect under clamping
- Do not use blind tapped holes in brass without a through bore nearby, because drill break-through tears the exit side and the chip packs into the thread
- Avoid sharp internal corners and specify fillets at least one third of the pocket depth to keep the cutting edge engaged
- State press-fit and interference requirements separately from general tolerance, since a bushing for a 12 mm shaft needs a different bore tolerance than a cosmetic cover
- Plan parting or parting-line-free turning for sealing faces, because a leaded brass part that is opened after plating will show a bright unwetted band
- Add a relief groove or undercut where a thread must run to a shoulder, otherwise the tool has to cut the thread in two passes and the crest height comes out low
- Keep deep bores to a length-to-diameter ratio of 4:1 or less, or specify a through hole and a second operation from the other end
- Provide a flat datum and a clamping reference so the second operation repeats without re-indicating every part
- Upload STEP, IGES or DXF files and get a free DFM report within 24h covering stock diameter, tooling, bore depth, thread runout and plating allowance
Tooling & Capacity
| Type | Lead Time | Suitable For |
|---|---|---|
| No Tooling (Direct Machining) | 3 - 5 working days | From 1 to 100 pcs for prototypes, replacement parts and one-off turned fixtures |
| Dedicated Fixture or Soft Jaw | 1 - 2 weeks | 100 to 10,000 pcs, repeat orders where fixture and setup time governs the cost |
| Production Machining Cell | Integrated with order | 10,000+ pcs with bar feeder, stable annual demand on a single part number |
| Plating and Finishing Line | 3 - 7 days added | Nickel, tin and chrome plated parts, blasted and polished parts, all coordinated in house |
Quality Assurance
- Each lot of incoming bar is checked against the mill certificate, with grade and heat number logged
- EN 10204 3.1 certificates are issued for each production batch on request
- Lead content verified on lead-free grades C377 and C48500 before machining starts, not sampled at final inspection
- A First Article Inspection report records full dimensional data against the 3D model
- CMM measurement of critical features including bore diameter, concentricity, runout and profile
- A calibrated profilometer verifies surface roughness on sealing and bearing faces
- Go and no-go thread gauges verify production threads
- Each setup change is inspected in process, not only at final inspection
- SGS, Bureau Veritas or TUV inspection is arranged at any stage on request for turned brass parts
- Brass lots ship with a dimensional report, material certificate and Certificate of Origin
Applications
- Hydraulic and pneumatic fittings and adapters
- Valve bodies, stems and actuator components
- Instrument panels, sensor bodies and connectors
- Marine hardware and seawater-exposed fittings
- Plumbing and sanitary fittings for potable water
- Electrical connectors and conductive bushings
- Bearing sleeves, spacers and wear rings
- Lighting hardware, lamp bases and decorative trim
- Automotive and motorcycle trim components
Why Choose FHY Precision
One supplier covers free-cutting, lead-free, naval and cartridge brass, so compliance and machining advice arrive with the quote
A ±0.02mm tolerance on critical features is proven with CMM data, not a catalogue claim
MOQ of 1 piece lets you approve a design before committing to a production batch
Free DFM report within 24h covering stock diameter, bore depth, thread runout and plating allowance
Plating and polishing coordinated under the same purchase order, so finished parts ship ready for assembly
Turning is backed by a documented quality system with third-party inspection and EN 10204 3.1 mill certificates on request
Turned in our own China shop and priced factory-direct, no trading layer
We keep stable capacity for repeat orders from a single prototype pc to 10,000 pc per year
FAQ
1. What is your minimum order quantity for brass CNC turning?
MOQ is 1 piece for turned brass parts. CNC turning cuts directly from bar, so there is no tooling charge and a single prototype is quoted on the same basis as a production order. Most first orders run 1 to 50 pieces, and repeat orders typically settle between 200 and 5,000 pieces per release once the drawing is fixed.
2. Which brass grades do you machine?
We machine C360 free-cutting brass, C377 leaded-free brass, C464 naval brass, C48500 HPB, C260 cartridge brass and CZ121 CuZn37. The choice depends on the environment and the compliance regime: C377 for potable water and food contact, C464 for seawater, C360 for general hardware where speed of cutting matters most. Send the application and we will recommend two options with the cost difference.
3. Is C360 brass safe for drinking water applications?
No. C360 carries around 3% lead, far above the 0.25% weighted average allowed for potable water fittings and above the 0.1% threshold most food contact rules apply, so it is ruled out in both regimes. For those applications we machine C377 with 0.3% lead, and we can issue the mill certificate showing the actual lead content of the specific heat before parts ship. If your drawing calls for C360 on a water-contact part, we will flag it during DFM review.
4. What tolerance can you hold on brass parts?
Critical features are held to ±0.02 mm, and ±0.01 mm is possible on short turned features and ground diameters. General dimensions follow ISO 2768-m at ±0.1 mm. Brass is dimensionally stable after machining, so tolerances hold without the post-machining movement that steel parts show after heat treatment. We report actual CMM values rather than nominal targets.
5. How fast can brass be machined compared to aluminium?
C360 brass cuts faster than free-machining steel but slower than 6061 aluminium, typically at 150 to 250 m/min surface speed with a positive rake carbide or coated insert. The 3% lead content breaks chips well and reduces the risk of edge built-up, which is the main reason leaded brass is chosen for high-volume turned work.
6. Can you produce threads and knurled surfaces?
Yes. We cut and form threads from M2 to M40, plus UNC, UNF, BSP, NPT and G, with go and no-go gauge verification on production threads. Knurling, serrations, splines, keyways, cross holes and fine boring are handled in house. Thread callouts should include depth and class, since a 6H versus 6G fit changes the die and the inspection method.
7. How do you prevent brass parts from tarnishing?
Tarnish is a natural reaction of copper with oxygen, sulfur and moisture, and it cannot be stopped completely without a protective layer. We ship machined parts with a corrosion inhibitor film or VCI paper, and we handle parts with clean gloves and oil-free fixtures to avoid fingerprint marks. For long storage or display use, clear lacquer or a sealant coating is the practical answer.
8. What surface roughness do you achieve as machined?
Standard as-machined surfaces are Ra 1.6 μm, with Ra 0.8 μm on a finish pass for sealing and bearing faces. Mechanical polishing reaches Ra 0.2 μm when a gasket or O-ring needs a finer surface, and brass polishes quickly because it is softer than steel. Surface roughness is checked with a calibrated profilometer and reported on the inspection sheet.
9. Can you supply a free DFM report before we order?
Yes. Upload a STEP, IGES or DXF file and we return a DFM report within 24 hours. For brass parts the review covers bar diameter versus part diameter, bore depth and whether it can be reached in one pass, thread runout against the shoulder, lead content against the intended application, and how much stock to leave for plating. The report is free and carries no obligation to order.
10. Do you machine brass bores and blind holes?
Yes, but depth to diameter matters. We recommend a length-to-diameter ratio of 4:1 or less for a blind bore machined in one pass, because deeper bores need a retract and a second operation, and the chip has to be cleared twice. Cross holes and angled features are machined with indexed setups on a mill-turn machine, which keeps concentricity tight without re-fixturing on a separate machine.
11. Can you supply plated or finished brass parts?
Yes. Nickel phosphorus, tin, tin-nickel and trivalent chrome plating are applied in house, as are glass bead blasting, mechanical polishing and clear lacquering. Plating is coordinated after dimensional inspection so the coating thickness is factored into the final dimensions. Brass parts for plating need a slightly larger machining allowance than bare parts, and the DFM report flags this.
12. How long does a brass machining order take?
Prototypes and small batches ship in 3 to 5 working days after drawing approval. Orders with plating or polishing add 3 to 7 days because the parts travel through the finishing line in sequence. Repeat orders with a dedicated fixture typically run 7 to 12 days for 1,000 to 5,000 pieces, depending on the number of setups and the bar stock diameter.
13. Do you provide material certificates?
Every lot ships with a mill certificate showing grade, heat number and chemical composition. EN 10204 3.1 material certificates are issued on request, and for lead-free grades we can confirm the measured lead content on the certificate. If your quality plan needs the certificate before parts ship, we send the scan with the inspection report so you can release the order in advance.
14. What information do you need to quote a brass part?
A 3D model in STEP or IGES, a 2D drawing with tolerances and surface callouts, the brass grade with any lead content requirement, quantity per release, and any plating or finishing requirement. If the drawing is incomplete, tell us the function of the part and we propose tolerances for the features that matter. Quotes come back within 24 hours on working days.
15. Do you offer third-party inspection?
Yes. We arrange inspection by SGS, Bureau Veritas or TUV at any stage you specify, from incoming material verification to pre-shipment dimensional checks. You receive a neutral report from an inspector you did not appoint, which is often what an end customer or auditor requires before accepting a first lot from a new supplier. We can also add a RoHS or REACH declaration to the shipment documents on request.
16. How do you handle repeat orders and consistency?
Drawings, CAM programs, fixture designs and inspection plans are archived against the part number, so a repeat order runs on the same setup and tooling as the first lot. We keep the first article report on file and compare new lots against it, which is why bores and threads stay stable across releases even months apart. Fixtures are stored for two years at no charge.