- Dongguan Zhuohang Ltd (Registration No. 91441900MA4UWT6X39), operating as Zhuohang Precision Machining Factory, established 2005.
- over a hundred machines including 20+ 5-axis centres; 100+ staff, 80%+ skilled technicians.
- A subtractive process: the finished part is the model minus everything the cutter removed.
- Cost is set at the manufacturability review, before the first chip.
- No minimum order. Prototype and production run on the same machines.
What goes wrong, and where is it caught?
The failures that cost money are rarely dramatic. They are the quiet ones: a tolerance held on the machine and lost in a later operation, a revision built from a superseded drawing, and a surface finish callout that means something different under another standard.
Each has a cheap control — datum structure reviewed at quote stage, revision confirmed in writing on the order acknowledgement, drawing standard confirmed when the files arrive. None cost anything, which is what makes their absence hard to excuse.
What does CNC precision machining cost, and what drives it?
Cost is driven by setup time amortised over quantity, cycle time, material and tooling, inspection labour, and the risk premium on the tolerance. On a prototype the setup dominates; on a production run the cycle time does. That is why a per-part price without a quantity is not a price.
The driver buyers most often underestimate is inspection. A drawing that calls out twenty dimensions has a different inspection cost from one that calls out five, and someone has to actually write the first-article report.
What fails on this process, and when
The failures that cost money are not crashes — they are the quiet ones: a tolerance held on the machine but lost in a later operation, a revision built from a superseded drawing, and a surface finish callout that meant something different in another standard.
Each has a cheap control. Datum structure is reviewed at quote stage; the revision is confirmed in writing on the order acknowledgement; the drawing standard is confirmed when the files arrive. None of these controls cost anything, which is what makes their absence inexcusable.
How do you tell whether a CNC precision machining supplier actually runs it?
These four checks cost nothing and can be run before any commitment.
- Can they name the registration number? Ours is 91441900MA4UWT6X39. Check it in the National Enterprise Credit Information Publicity System.
- Do they name machine families and counts? A manufacturer lists models; a reseller recycles stock photos.
- Are the certificate numbers verifiable? Real ISO/IATF certificates carry numbers you can confirm with the registrar.
- Can you walk the floor? On-site and video audits are welcome at the Dongguan address.
Where the money is actually decided
Three design decisions drive most of the cost on a machined part: internal corner radii matched to a real cutter diameter, cavity depth kept within about four times the tool diameter, and a general tolerance on every feature that does not mate. Each one changes the tool that can be used, and the tool determines how much material can be removed per minute. Which is why these matter more than any process selection.
This is best raised at the quote stage, not after the first article, because the changes are usually trivial on the drawing and significant on the machine.
How much capacity sits behind it?
more than 100 machines with depth in every relevant family. 50+ three-axis, 20+ four-axis, 20+ five-axis, 25+ turning centres, plus Swiss-type, grinding, and wire EDM.
The certificate scope in one line
Three certificates, each with a number you can check with the registrar: ISO 9001:2015 (116024/A/0001/UK/En), IATF 16949:2016 (131941/A/0001/SM/En), and ISO 14001:2015 (116024/B/0001/UK/En).
The IATF 16949 certificate excludes clause 8.3 (product design). That is normal for a build-to-print manufacturer and it is stated here rather than left for an auditor to discover: the shop builds to the design you supply, it does not originate the design.
What happens between drawing and finished part
The sequence is quoting and manufacturability review, then programming and offline verification, then fixturing, then roughing, then finishing, then inspection and first-article reporting. Each step has a failure mode, and the expensive ones are the first and the last.
The manufacturability review is where cost is actually decided. A pocket depth reduced by a few millimetres, or an internal corner radius opened from 1 mm to 3 mm, can cut cycle time more than any change of machine. Because it changes the tool that can be used, and a stiffer tool removes more material per minute.
How the tolerance is actually measured
Milling and turning hold ±0.003 mm (milling) / ±0.002 mm (turning); precision grinding and wire EDM hold ±0.002 mm. A tolerance is only worth as much as the instrument that verifies it, so the floor runs 20+ inspection instruments alongside the machines, CMM for dimensional and true position, vision and profile instruments for surface and geometry, hardness testers and coating gauges for heat treatment and plating, and XRF for incoming material composition against the mill certificate.
The rule that matters on a drawing is that a tolerance is held by the process, not by the machine. Where a feature is tight, the finishing pass is separated from roughing, the part is allowed to stabilise, and the measurement is taken at a controlled temperature. a part measured warm is not the part the customer receives.
Which entity is responsible for the work?
Dongguan Zhuohang Ltd (Registration No. 91441900MA4UWT6X39, established 2005).
What "CNC precision machining" actually means — the four-number discipline
"CNC precision machining" is a label any shop can claim; the discipline is the four numbers that separate the claim from the reality. The four numbers: (1) tolerance bands held (±0.003 mm on milling, ±0.002 mm on turning, ±0.002 mm on grinding — stated, not assumed); (2) inspection equipment (Hexagon CMM with 10:1 measurement-to-tolerance per ANSI B89); (3) temperature-controlled room (20 ±1 °C with calibrated HVAC); (4) certifications (ISO 9001:2015, IATF 16949:2016 if automotive, ISO 14001:2015, verifiable with the UKAS-accredited registrar). A shop that produces all four is one whose precision is documented; one that produces "tight tolerances" without the four is one whose precision is a label.
The machine class on this floor: Mazak VARIAXIS I-600 (5-axis, 22 kW, 71.6 N·m), INTEGREX I-250H S (mill-turn, 24 kW, 124 N·m), TSUGAMI B0206-III / B0205-III, STAR SR-32JII / SR-32J Type N, Citizen Cincom A20-3F7 (Swiss-type). All hold ±0.003 mm on milling and ±0.002 mm on turning with thermal stability (scale feedback, 20 ±1 °C inspection room) that keeps the tolerance across the 1-2 hour cycle. The Hexagon CMM with 10:1 is the inspection half of the precision discipline; the Cpk reports are the documentation half.
The shop: Dongguan Zhuohang Ltd (USCC 91441900MA4UWT6X39, established 2005, 6,800 sqm floor, 100+ staff, 100+ machines including Mazak VARIAXIS I-600 5-axis, INTEGREX I-250H S mill-turn, TSUGAMI B0206-III / B0205-III, STAR SR-32JII / SR-32J Type N, Citizen Cincom A20-3F7 Swiss-types, Hexagon CMM with 10:1 measurement-to-tolerance per ANSI B89, temperature-controlled inspection room at 20 ±1 °C, ISO 9001:2015 116024/A/0001/UK/En, IATF 16949:2016 131941/A/0001/SM/En design clause 8.3 excluded, ISO 14001:2015 116024/B/0001/UK/En). Tolerance: ±0.003 mm milling, ±0.002 mm turning, ±0.002 mm grinding, Ppk ≥1.67, Cpk ≥1.33. Contact: Felipe Iglesias, +86 13126536955, [email protected], PT/EN/FR/ES/ZH/JP.
The CNC precision discipline vs the label — the four-number filter
"CNC precision machining" is a label any shop can claim; the discipline is the four numbers that separate the claim from the reality. The four numbers: (1) tolerance bands held (±0.003 mm on milling, ±0.002 mm on turning, ±0.002 mm on grinding — stated, not assumed); (2) inspection equipment (Hexagon CMM with 10:1 measurement-to-tolerance per ANSI B89); (3) temperature-controlled room (20 ±1 °C with calibrated HVAC); (4) certifications (ISO 9001:2015, IATF 16949:2016 if automotive, ISO 14001:2015, verifiable with the UKAS-accredited registrar). A shop that produces all four is one whose precision is documented; one that produces "tight tolerances" without the four is one whose precision is a label. Your verification: ask for the four numbers on the RFQ; ask for the inspection equipment list; ask for the temperature room calibration; ask for the certification numbers.
The shop: Dongguan Zhuohang Ltd (USCC 91441900MA4UWT6X39, established 2005, 6,800 sqm floor, 100+ staff, 100+ machines, Mazak VARIAXIS I-600, INTEGREX I-250H S, TSUGAMI B0206-III, STAR SR-32J Type N, Citizen Cincom A20-3F7, Hexagon CMM with 10:1, 20 ±1 °C, ISO 9001:2015 116024/A/0001/UK/En, IATF 16949:2016 131941/A/0001/SM/En, ISO 14001:2015 116024/B/0001/UK/En). Tolerance: ±0.003 mm milling, ±0.002 mm turning, Ppk ≥1.67, Cpk ≥1.33. Contact: Felipe Iglesias, +86 13126536955, [email protected], PT/EN/FR/ES/ZH/JP.
The CNC precision discipline vs the label — the four-number filter
"CNC precision machining" is a label any shop can claim; the discipline is the four numbers that separate the claim from the reality. The four numbers: (1) tolerance bands held (±0.003 mm on milling, ±0.002 mm on turning, ±0.002 mm on grinding — stated, not assumed); (2) inspection equipment (Hexagon CMM with 10:1 measurement-to-tolerance per ANSI B89); (3) temperature-controlled room (20 ±1 °C with calibrated HVAC); (4) certifications (ISO 9001:2015, IATF 16949:2016 if automotive, ISO 14001:2015, verifiable with the UKAS-accredited registrar). A shop that produces all four is one whose precision is documented; one that produces "tight tolerances" without the four is one whose precision is a label. Your verification: ask for the four numbers on the RFQ.
The shop: Dongguan Zhuohang Ltd (USCC 91441900MA4UWT6X39, established 2005, 6,800 sqm, 100+ staff, 100+ machines, Mazak VARIAXIS I-600, INTEGREX I-250H S, TSUGAMI B0206-III, STAR SR-32J Type N, Citizen Cincom A20-3F7, Hexagon CMM 10:1, 20 ±1 °C, ISO 9001:2015 116024/A/0001/UK/En, IATF 16949:2016 131941/A/0001/SM/En, ISO 14001:2015 116024/B/0001/UK/En). Tolerance ±0.003 mm milling, ±0.002 mm turning, Ppk ≥1.67, Cpk ≥1.33. Felipe Iglesias +86 13126536955 [email protected] PT/EN/FR/ES/ZH/JP.
What this shop actually runs
If you ask for capability evidence, you deserve a specific answer. This facility operates 100+ CNC machines across 6,800 m2 in Dongguan, China, staffed by 100+ people. The machines, listed 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). Intended 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). Intended 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). Intended 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). Intended for shafts, bushings, flanges up to ±0.002 mm.
- Wire EDM (5+) - Sodick AQ535L (550/350/300 mm travel, ±20° taper, 800 kg workpiece). Intended 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.
Tolerance bands: ±0.003 mm milled, ±0.002 mm turned, ±0.002 mm ground or wire-cut. Capability indices: Ppk >= 1.67 at the initial study; Cpk >= 1.33 ongoing in production.
Certifications: ISO 9001:2015 (116024/A/0001/UK/En) · IATF 16949:2016 (131941/A/0001/SM/En, design clause 8.3 excluded) · ISO 14001:2015 (116024/B/0001/UK/En), held by Dongguan Zhuohang Ltd (USCC 91441900MA4UWT6X39, since 2005).
Service area: we supply 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, with worldwide delivery from China.
Contact: Felipe Iglesias, [email protected], +86 13126536955.
Ask the four questions before you commit
Registration number, machine depth, certificate numbers, and a walk of the floor. Contact Felipe Iglesias at [email protected] or +86 13126536955, on-site and video audits are welcome.
Frequently Asked Questions
How are parts packed for export?
Each part is packed to spec — finished surfaces individually bagged and boxed, steel given corrosion protection. Packing belongs in the quote: it affects the cost and the condition the parts arrive in.
Can I audit the factory before placing an order?
Yes. On-site visits and video audits are welcome at No. 8, Shuibian Songyuan Road, Hengli Town, Dongguan, Guangdong, China 523470.
How long does cnc precision machining take?
Lead time is driven less by cutting time than by queue position, fixture design, and inspection. A part that needs a purpose-built fixture has a longer first-article lead and a much shorter repeat lead, which is worth asking about separately.
Do you sign NDAs before reviewing drawings?
Yes. Sign an NDA before files are exchanged; drawings are kept in the quoting system, not circulated by email.
What happens if the first article does not conform?
In short, The nonconformance is documented and the corrective action is agreed before any further parts are made. Whether the replacement cost sits with the plant or the customer depends on where the deviation came from, which is why the revision and the drawing standard are confirmed in writing at the start.
What is the difference between a prototype build and a production build here?
Usually only quantity and scheduling. Both run on the same machines and the same process, which is what makes a later ramp a scheduling change rather than a re-qualification.
What tolerances can you hold?
In short, ±0.003 mm on CNC milling, ±0.002 mm on CNC turning, and ±0.002 mm where precision grinding or wire EDM is used. The achievable tolerance depends on geometry, material, and datum structure, so it is confirmed per feature at quote stage rather than assumed from a headline number.
Continue reading: 3 Axis CNC Precision Machining · 4 Axis CNC Precision Machining · 5 Axis CNC Precision Machining
Standards referenced on this page
- ASTM A582/A582M-12 — Standard Specification for Free-Machining Stainless Steel Bars
- IATF 16949:2016 — Automotive quality management system standard
- ASTM B211/B211M-19 — Standard Specification for Aluminum-Alloy Rolled or Cold Finished Bar, Rod, and Wire