CNC Machining Factory Services
Grinding is the process that takes a dimension past where a cutting tool can reliably hold. Where milling and turning hold ±0.003 mm (milling) / ±0.002 mm (turning), grinding holds ±0.002 mm, which is why it is reserved for bearing seats, precision shafts and surfaces that need roundness and finish beyond what a cutter can deliver.
The three forms — surface, centerless and cylindrical — cover different geometries. Surface grinding flattens faces; centerless grinding holds outside diameters on long or thin parts without a center hole; cylindrical grinding holds outside and inside diameters to tight roundness. If your print calls out a bore or journal at ±0.002 mm, confirm the supplier has the grinder in-house and the CMM to measure the result, not just the word "precision" on a website.
Grinding is also where surface finish and dimension meet. A ground bearing journal reaches a Ra the mill cannot, because the abrasive removes material differently from a cutter — it is not just a tighter dimension, it is a different surface. If your part has a sealing face or a sliding surface, confirm the finish callout is measured, not assumed, and that the same lab owns the profilometer that reports it.
Which secondary services can be bundled?
Most parts are not finished when they leave the machine. You should know which secondary operations can be bundled under one accountable supplier, and which are handled by a partner.
- Surface finishing: standard and hard anodizing, zinc / nickel / silver / gold / chrome plating, powder coating, painting, brushing and mirror polishing.
- Heat treatment: vacuum, bright, carburizing, nitriding and stress-relief aging. In-house ovens reach 500 °C (fine for aluminum and low-temperature steel stress relief); titanium stress relief above that is outsourced to a qualified partner and stated as such.
- Post-machining: deburring, tapping, laser marking and assembly as the print requires.
Any surface finishing pushes a part into the longer lead-time tier. Complex parts can run 10–20 process steps; tell the supplier your target date and it should tell you honestly whether it holds.
The bundling question matters because every secondary step adds a handoff, and every handoff is a place lead time and accountability can leak. When a supplier bundles finishing and heat treatment, ask whether those steps appear in the traceability record — a part that left for anodizing and came back should carry that loop in its chain, not vanish into "finished" without a note. A supplier that documents the partner's step is holding the whole job accountable; one that does not is handing you the part and hoping you do not ask where it went.
How are parts verified before they ship?
A service is only worth the measurement behind it. Dimensional verification runs on in-house Hexagon CMMs, surface finish on a profilometer, and material composition on XRF against the mill certificate, so the alloy, the size and the surface are all checked, not assumed.
The proof is a document, not a claim. Ask for a dimensional report and read it: every critical dimension should carry a measured value, not a pass/fail flag. "OK" is an opinion; "10.0013 mm" is a measurement. CMM reports and SPC charts ship with the parts, giving you the evidence to hold the supplier accountable, and to accept the batch without a second guess.
What materials do these services cover?
The material you specify dictates the tooling, speeds and verification a service must support. These services run the alloys buyers actually put on drawings, and verify every incoming lot by XRF against its mill certificate before it goes on a machine, so the material you ask for is the material you get.
| Family | Grades | Best for |
|---|---|---|
| Aluminum | 6061, 6063, 6082, 7075 | Lightweight housings and prototypes |
| Stainless steel | 303, 304, 316, 316L, 17-4PH | Corrosion and strength-critical parts |
| Carbon / alloy steel | 1018, 1045, 4140, 4340 | Wear parts, carburized or nitrided |
| Brass / copper | C360, H62, C110 | Electrical and thermal conductivity |
| Titanium | TA2, TC4 (Grade 2 / 5) | Weight-critical, corrosion-resistant parts |
| Engineering plastics | ABS, POM, nylon, PTFE, PEEK | Insulators and non-metal prototypes |
What should you check before ordering a machining service?
The same questions separate every real machining service from a resold one, and they are all answerable in one exchange.
- Which services run in-house, and which are subcontracted? A supplier should name the line between them, not blur it.
- What tolerance can it hold in production — with a report to prove it? ±0.003 mm milling / ±0.002 mm turning and ±0.002 mm grinding, backed by a CMM report on a similar part.
- Is the CMM in-house, and does the report ship with every batch? The lab is the guarantee.
- Are the certificate numbers verifiable? ISO 9001, IATF 16949 and ISO 14001 numbers you can check with the registrar against the legal name.
- Who owns the secondary operations? If finishing or heat treatment is outsourced, the supplier should say so and name the partner.
Send a drawing to [email protected] and this operation runs all five checks on itself for you, in writing, before you commit.
What this shop actually runs
Ask for capability evidence and the answer should be specific. The facility behind this guide runs 100+ CNC machines on a 6,800 m2 floor in Dongguan, China, with 100+ staff. The machine list, by category:
- 5-axis machining centres (10+) - Mazak VARIAXIS I-600 (510/910/510 mm travel, 12,000 rpm, 22 kW, 71.6 N·m, 30-tool BT40) and Mazak INTEGREX I-250H S (B-axis 0.0001°, 24 kW, 124 N·m, 38-tool HSK-A63). Chosen for compound-angle parts, single-setup multi-face prismatic work, and aerospace fittings where datum transfer loss is unacceptable.
- 3-axis / 4-axis machining centres (50+) - Brother SPEEDIO S500Z2N / S700Z2N (10,000 rpm, 14/21-tool ATC, 0.7 s tool-to-tool, Z-axis 2.2 G) and Mazak VCE-430A L / VCE-570C L (10,000 rpm, 118 N·m, 24-tool ATC). Chosen for prismatic parts, plates, brackets, housings.
- Swiss-type turning centres (10+) - Citizen Cincom A20-3F7 (Φ20 mm, 10,000 rpm), TSUGAMI B0206-III / B0205-III (Φ20 mm, 0.1 µm), STAR SR-32JII / SR-32J Type N (Φ32 mm, 8,000 rpm). Chosen for long, slender rotational parts at ±0.002 mm.
- CNC turning centres (20+) - HEADMAN T70M/1250 (720 mm swing, 117 mm bore, 3,000 rpm, BMT75 12-station turret). Chosen for shafts, bushings, flanges up to ±0.002 mm.
- Wire EDM (5+) - Sodick AQ535L (550/350/300 mm travel, ±20° taper, 800 kg workpiece). Chosen for hardened tool steel, internal splines, sharp internal corners that milling cannot reach.
- Inspection: Hexagon CMM + 20+ gauges - Hexagon CMM for coordinate measurement, plus vision system, profilometer, hardness tester, coating thickness gauge, XRF for material verification. The 10:1 rule (gauge 10x more accurate than the band) is applied to every feature.
- Machine highlights - VARIAXIS I-600: one-setup multi-face 5-axis + MAZA-CHECK auto-calibration; INTEGREX I-250H S: DONE-IN-ONE mill-turn, B-axis 0.0001° + Ai thermal shield; SPEEDIO S500Z2N / S700Z2N: Z-axis 2.2 G + 0.7 s ATC; Swiss-type: guide-bush switchable + 0.1 µm resolution.
Tolerances held: milling ±0.003 mm, turning ±0.002 mm, grinding and wire EDM ±0.002 mm. Capability: Ppk >= 1.67 initial and Cpk >= 1.33 in production on key characteristics.
Certifications: ISO 9001:2015 (116024/A/0001/UK/En), IATF 16949:2016 (131941/A/0001/SM/En, clause 8.3 design excluded, disclosed openly) and ISO 14001:2015 (116024/B/0001/UK/En), issued to Dongguan Zhuohang Ltd, USCC 91441900MA4UWT6X39, established 2005.
Service area: Austria, Belgium, the Czech Republic, Denmark, France, Germany, Greece, Hungary, Ireland, Italy, the Netherlands, Spain, Sweden and the United Kingdom in Europe; Brazil, Canada, Mexico and the United States in the Americas; China, Israel, Japan, Singapore and Sri Lanka in Asia; Australia and New Zealand in Oceania; and South Africa in Africa — built in China, shipped worldwide.
Contact: Felipe Iglesias, [email protected], +86 13126536955.
Ready to source a machining service you can verify?
Send your drawing to [email protected] or call +86 13126536955 for a DFM review and quote.
Frequently Asked Questions
Which CNC machining services do you run in-house?
In short, Milling, turning, mill-turn and grinding all run in-house on an 100+ machine fleet. Surface finishing such as anodizing and plating, and heat treatment, are handled through qualified partners and stated honestly rather than implied as internal capability.
What is the difference between 3-axis, 4-axis and 5-axis milling?
In short, Three-axis moves the tool in X, Y and Z for prismatic parts. Four-axis adds a rotary table to machine multiple faces without re-clamping.
What tolerances do your services hold?
In short, Milling and turning hold ±0.003 mm (milling) / ±0.002 mm (turning); precision grinding holds ±0.002 mm. Critical dimensions are verified on in-house Hexagon CMMs, with process capability Ppk ≥ 1.67 at the initial study on key characteristics and Cpk ≥ 1.33 on general characteristics.
Can you bundle surface finishing and heat treatment?
In short, Yes — standard and hard anodizing, zinc, nickel, silver, gold and chrome plating, powder coating, painting, brushing and polishing can be bundled, along with heat treatment. In-house ovens reach 500 °C; titanium stress relief above that goes to a qualified partner.
What is the minimum order quantity for machining services?
The MOQ is 1 piece, so you can prototype and validate a design before committing to a production run. Lead time is roughly 3, 7 or 30 days depending on part complexity and the number of process steps involved.
How do you verify machined parts before shipping?
In short, Dimensional verification runs on in-house Hexagon CMMs, with surface finish checked on a profilometer and material composition confirmed by XRF against the mill certificate. CMM inspection reports and SPC charts ship with the parts so you receive documented evidence, not a pass/fail claim.
Which materials can your machining services process?
In short, Aluminum, stainless steel, carbon and alloy steel, brass, copper, titanium, magnesium and engineering plastics including ABS, POM, nylon, PTFE and PEEK. Every incoming lot is XRF-checked against its mill certificate so the alloy you specify is the alloy you receive.
How do I get a quote for CNC machining services?
Send your STEP, IGES or 2D drawing to [email protected]. You receive a design-for-manufacturing review and a quote, usually within one business day, with any DFM issues flagged before you commit rather than discovered after the parts are cut.
How do I choose between milling and turning for my part?
In short, Look at the part's symmetry. A prismatic part — flat faces, pockets, holes — points to milling.
Why does single-setup mill-turn reduce tolerance risk?
In short, Because every re-clamping adds a location error. When a shaft's milled flat and turned journal share a datum, machining both in one setup holds the relationship directly; two setups hold it by hoping the fixtures line up.
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Standards referenced on this page
- ASTM B211/B211M-19 — Standard Specification for Aluminum-Alloy Rolled or Cold Finished Bar, Rod, and Wire
- ASTM B348/B348M-21 — Standard Specification for Titanium and Titanium Alloy Bars and Billets
- ISO 9001 — Quality management systems — Requirements