Precision CNC milling services · Dongguan factory

Precision CNC milling for the parts other shops send back

Multi-face parts, thin walls, deep pockets, and plated sizes. Trading companies have long passed their difficult milling jobs to our shop. Now you can order from us directly.

One clamping on 3+2Features on several faces stay aligned to each other.
Sizes cut for plating8.245 mm before nickel, for 8.25 ±0.02 mm after.
Checked on our own CMMPositions, profiles, and GD&T verified in-house.
Down to Ra 0.2 µmAs machined, without extra polishing.

Send Your Difficult Drawing 3-axis vs 3+2 milling

DFM feedback before the priceRisky features flagged in the quote

Free first-article reportOn your first order

Fast repliesEmail within 24 h, WhatsApp within 12 h

Brass frame milled on a 3+2 machining center, with tapped holes on raised faces, thin lugs, a long slot, and side bores

Precision CNC milling means cutting a part from solid metal or plastic on a computer-controlled machining center, with tolerances in the hundredths or thousandths of a millimeter. A rotating cutter removes material while the machine moves the part in three axes. On a 3+2 machine, two rotary axes tilt and lock the part between cuts, so several faces are machined in one clamping and stay accurate to each other.

Precision in numbers

What our milled parts are held to

Feature	What we hold
Features on the same face	0.005 mm
Positions between different faces	0.01 mm, in one 3+2 clamping
Standard milled features	±0.05 mm
Flatness on large plates	0.02 mm, for example over 500 mm
Surface finish	Down to Ra 0.2 µm as machined

Milling is about 60% of our work. We run 10 3+2 machining centers for multi-face parts and 5 3-axis machines for larger plates and housings up to about 1000 × 400 × 200 mm.

How we hold it

Faces that line up, plates that stay flat

One clamping for related faces. Features on several faces are cut in one 3+2 setup, so positions between faces do not depend on re-clamping. That is how 0.01 mm across faces is held.
Flat large plates. 0.02 mm flatness on a big plate comes from special workholding and finishing with a small tool at the right feed, after the part has been roughed and released. It cannot be rushed.
Verified, not assumed. Positions, profiles, and GD&T callouts are measured on our in-house CMM; flatness is checked on a granite plate.
Lead time. Simple milled parts in about 3 days, complex parts from about 7 days.

Our 3+2 machines tilt and lock the part; they do not cut in five axes simultaneously. Freeform surfaces that need full five-axis milling are not a good fit for us, and we will say so at drawing review rather than quote a job we cannot do well.

Matte black anodized 6061 aluminum robot equipment bracket with deep pockets and features on several faces — Robot equipment bracket, 6061, black anodized.

6061 aluminum · 3+2 · one setup

A robot bracket with tolerances on several faces

This bracket for robot equipment has many pockets and geometric tolerances on several faces that must relate to each other. Machined in separate setups, every re-clamp would add its own error.

We designed a special fixture and machined it on a 3+2 center in one setup, so the faces stay true to one datum. The parts were then black anodized and re-checked.

Send a multi-face drawing

Milled parts we make

CNC milled parts from our shop floor

Real parts, photographed after inspection, with the challenge that made each one hard. If yours looks similar, we have made it before.

Angled 5083 aluminum assembly part with features on several faces

5083 aluminumAutomation equipment

Angled automation bracket

Challenge: Irregular shape with features at several angles, machined complete in one 3+2 clamping.

6061 aluminum automation block with pins, pockets, and features on several faces

6061 aluminumAutomation equipment

Multi-face automation block

Challenge: Features on several faces with many related dimensions that must line up after assembly.

Clear polycarbonate machined cover with a curved channel and mounting holes

Transparent PCMedical equipment

Clear cover for a medical device

Challenge: Cosmetic part: no scratches, tool marks, or haze anywhere on a clear surface.

6082 aluminumTobacco machinery

Thin-wall flange

Challenge: Thin, irregular wall on 3+2, with H7/g6 fits on inside and outside diameters plus a runout callout.

Small white nylon part with a row of precision micro holes

NylonAutomation equipment

Small precision nylon part

Challenge: A small part with tight sizes and precision micro holes that must be free of burrs.

PEEK part with turned bore, milled features, and brass threaded inserts

PEEKTurn-mill part

PEEK part with threaded inserts

Challenge: Turned and milled features with many precise dimensions, then threaded inserts fitted.

Milling capability

3-axis or 3+2: what each can make

15 machining centers: 10 for 3+2 multi-face work and 5 for larger 3-axis parts. We choose the route for each part at drawing review, so you don't have to.

3-axis

3-axis milling

Machines: 5 in-house
Max part size: 1000 × 400 × 200 mm
Standard tolerance: ±0.05 mm
Precision: 0.005 mm on one face, 0.01 mm across faces

Best for

Plates, brackets, covers, and housings
Features on one or two faces
Larger parts up to 1 m long

3+2 machining center cutting under coolant, with the part clamped on a tilting rotary trunnion table

3+2

3+2 multi-face milling

Machines: 10 in-house
Max part size: approx. 300 × 250 mm
Standard tolerance: ±0.05 mm
Precision: 0.005 mm on one face, 0.01 mm across faces

Best for

Angled holes and features on 3+ faces
Related dimensions across faces
Irregular parts up to about 300 × 250 mm, in one clamping

Surface finish: Down to Ra 0.2 µm as machined
Inspection: In-house CMM, height gauge, projector, roughness tester
Quantities: Batches of 20 to 10,000 pcs; prototypes first
Lead time: Simple parts about 3 days, complex from 7 days

Batch pricing · 20 pcs and up

Milled parts cost far less from 20 pieces

Most of the cost of a one-off part is the work before the first chip: drawing review, programming, fixturing, and proving out the first part. On one piece, that piece carries all of it. On 20, it is shared twenty ways. Ask for prices at a few quantities, for example 5, 20, and 50, and we'll quote each one.

Quote My Batch How a CNC quote is built: why batches cost less → Low-volume production: batches of 20 to 10,000 pcs → Chamfers, fillets and inside corners: what changes the price →

Setup work carried by each part

1 pcall

5 pcs1/5

20 pcs1/20

CAM program and first-article check paid once per batch
At 20+ pieces a dedicated fixture pays for itself: faster loading, every part clamped the same way
3+2 machining finishes multi-face parts in fewer setups
Repeat orders reuse the program and fixtures

Materials

Materials we mill, and what each one needs

Grades we machine every week, with the detail that matters when milling each one. Grade not listed? Send the drawing and we confirm availability before quoting.

Material	Common grades	What we watch when milling it	Finishes
Aluminum	5083, 6060, 6061, 6082, 7075	Thin walls move as stress is released, so roughing and finishing are split and walls are finished last.	Anodizing incl. color and hard anodize (up to 50 µm), nickel plating, bead blast
Stainless steel	303, 304, 316, 440C	Work-hardens if the tool rubs. Sharp tools, steady feeds, and more deburring time than aluminum.	Passivation, electropolish, bead blast
Carbon & alloy steel	Q235, C45, 16CrMn5	Machined before hardening, with stock left for size change after QPQ or vacuum heat treatment.	QPQ, vacuum heat treatment, black oxide, zinc
Brass & copper	Brass, pure copper	Brass cuts cleanly for fine features; pure copper is gummy and needs sharp tools to avoid burrs.	As machined, nickel plating, polishing
Engineering plastics	POM, nylon, PEEK	Light clamping and sharp tools so the part does not distort, and micro holes come out free of burrs.	As machined; threaded inserts fitted
Clear plastics	Transparent PC	Cosmetic faces must stay free of scratches, tool marks, and haze, so they are protected through every step.	Flame polishing, polished clear faces

Properties and grade notes in the materials guide → Aluminum CNC machining →

Milling quality

Where milled parts go wrong, and how we prevent it

Most rejected milled parts fail for the same few reasons. These are the ones we plan for before the first cut.

RiskFlatness lost after unclamping

How we prevent itRough, release the part, re-clamp lightly, then finish. Flatness checked on a granite plate.

RiskThin walls bow or chatter

How we prevent itWalls finished last with light step-downs, and supported while they are cut.

RiskFaces that don’t line up

How we prevent itMulti-face features cut in one 3+2 clamping, positions verified on our CMM.

RiskWrong size after plating

How we prevent itCritical sizes cut with plating allowance, measured before the parts go out.

RiskBurrs in small holes and pockets

How we prevent itEvery feature deburred and checked before packing, not just the outside edges.

RiskSharp inside corners on the drawing

How we prevent itFlagged at review, with a corner radius or EDM option offered before you order.

After milling

Finished parts, not just machined ones

We arrange finishing with managed partners, plan the machined sizes around it, and inspect every part again when it comes back. One order, one contact, finished parts at your door.

Aluminum parts anodized blue, red, and black

Anodizing, incl. hard anodize

What we control: Hard anodizing up to 50 µm in a range of colors, with coating thickness allowed for on fits and threads.

Two nickel-plated 6061 aluminum housings

Nickel plating

What we control: Critical sizes cut undersize by the plating thickness, so they land in tolerance after plating.

QPQ-treated black steel fixture parts and a vacuum hardened block

QPQ and vacuum heat treatment

What we control: Steel machined before hardening, with stock left for size change; hardness confirmed on the drawing.

Clear polycarbonate cover with flame-polished edges and faces

Flame polishing for clear plastics

What we control: Machined edges flame polished back to full clarity, with faces protected from the first cut to packing.

Also arranged:Bead blastingBlack oxideZinc platingPassivationElectropolishingLaser markingThreaded inserts

Get a quote

Send what you have. Here is what we need.

A 2D drawing, a 3D model, or both. Each works, as long as we get the details the file itself can't show.

BestYou have a 2D drawing and a 3D model

The fastest, most accurate quote. The drawing carries the tolerances, the model carries the geometry.

12D drawing (PDF)23D model (STEP)

You only have a 2D drawing

That works if the drawing is clear and fully dimensioned. We build the 3D model ourselves. For complex parts, a 3D file is strongly preferred.

12D drawing (PDF)

You only have a 3D model

A model can't carry these, so tell us in your message. Features without a stated tolerance follow ISO 2768-m.

3Material5Heat treatment & finish4Quantity8Target date

Always helps:6Critical dimensions7How the part is used

Send it as one .zip, we take it from there

Drawing review and DFM feedback come with the quote. Email reply within 24 h, WhatsApp within 12 h. First order includes a free first-article report.

Send Your Drawing Package

Case notes

Milled features from recent case notes

Internal pockets in titanium and cross holes on a 3+2 machine, from real orders with measured results.

30 pcs

TC4 titanium

TC4 titanium prototypes

±0.05 mm on diameters and hole positions, Ra 1.6, M2 threads and Ø1.6 mm holes.

Read the case note

100 pcs

SUS430 stainless

SUS430 motor housings

A 10 µm band on Ø8. Micrometer readings 7.987 and 7.988 mm against 7.98–7.99.

Read the case note

48 pcs

304 stainless

Thin-wall 304 conical rings

Walls that distort in a normal chuck. A dedicated fixture turned in-house, two operations per ring.

Read the case note

All recent parts and case notes

FAQ

Common questions about CNC milling

A 2D drawing plus a 3D model (STEP) gives the fastest, most accurate quote. A clear, fully dimensioned 2D drawing is enough on its own: we build the 3D model ourselves, though for complex parts a 3D file is strongly preferred. If you only have a 3D model, tell us the material, heat treatment and finish, quantity, and target date; features without a stated tolerance follow ISO 2768-m.

Standard milled features are held to ±0.05 mm. Features on the same face can be held to 0.005 mm, and positions between different faces to 0.01 mm when the part is machined in one 3+2 clamping. Every critical tolerance is confirmed at drawing review before you order, and positions, profiles, and GD&T callouts are verified on our in-house CMM. How we hold tight tolerances across a batch →

Our limit today is 0.02 mm, for example over a 500 mm plate. It takes special workholding, roughing and releasing the part first, and finishing with a small tool at the right feed. Flatness is checked on a granite plate.

We run 10 3+2 machining centers: two rotary axes tilt and lock the part, so several faces are machined in one clamping. They do not cut in five axes at the same time, so freeform surfaces that need full five-axis milling are not a good fit for us.

We use 3+2 when a part has angled holes or features on three or more faces that must line up. The B and C axes tilt and lock the part, so those faces are machined in one clamping instead of several re-clamps. 3+2 suits parts up to about 300 × 250 mm; larger parts up to 1000 × 400 × 200 mm run on 3-axis machines. We choose the route at drawing review.

Finishing such as anodizing (including hard anodizing up to 50 µm in a range of colors), nickel plating, QPQ, vacuum heat treatment, and flame polishing of clear plastics is arranged with managed partners. We cut critical sizes with allowance for the coating, so fits and threads land in tolerance after finishing, and every part is inspected again when it comes back.

Yes, as the first step toward a batch: our main work is batches of 20 to 10,000 pieces per part number, and the prototype runs on the same machines and process. We review the drawing first and raise any questions before you confirm. Prototype unit cost is higher than batch pricing: from 20 pieces the unit cost drops sharply, because programming and fixturing are shared across the batch.

Simple milled parts take about 3 days and complex parts from about 7 days. Simple 6061 aluminum parts, a few pieces, can be rushed in 2 days from material in stock, with express shipping time added. We confirm the date per part number with each quote, before you order.

Drawing review with manufacturability feedback in the quote, a free first-article inspection report, and our remake guarantee: parts that do not meet your drawing are remade at our cost, with freight paid both ways. We reply by email within 24 hours and on WhatsApp within 12 hours.

Reviewed by Raymond Liang, co-founder, 15 years in CNC machining · Updated October 12, 2026

Got a milled part other shops turned down?

Send the drawing. You get DFM feedback with the quote and a free first-article report on your first order. Email reply within 24 hours, WhatsApp within 12 hours.

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