- ISO 9001:2015 / IATF 16949:2016 / ISO 14001:2015 — certificate numbers published and verifiable.
- Build-to-print manufacturing: the plant cuts to your design and reports against your drawing.
- A quote is only as good as the drawing behind it.
- The four omissions that turn an accurate quote into a revised one.
- Confirm revision, FAIR scope, and delivery terms in writing before release.
What to include with a 4 axis CNC milling drawing
A quote is only as good as the drawing behind it. The gap between a fast quote and an accurate one is almost always a missing tolerance scheme, an unspecified surface finish, or a material callout that names a family rather than a grade.
The five things that change the answer: the 3D model, the 2D drawing with tolerances, the material grade, the quantity (and the anticipated repeat quantity), and any inspection or certification requirement.
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 worth raising at quote stage rather than after the first article, because the changes are usually trivial on the drawing and significant on the machine.
Which entity is responsible for the work?
Dongguan Zhuohang Ltd, Registration No. 91441900MA4UWT6X39, in operation since 2005.
How much of the floor is in this family?
Total machine count is not the question, the question is how many machines sit in the family that makes your part, because that is the queue your part waits in. The floor runs over a hundred machines: 50+ three-axis centres for prismatic work, 20+ four-axis, 20+ five-axis, 25+ turning and mill-turn centres, Swiss-type lathes for long slender parts, precision grinding and wire EDM for the tightest features.
The spare capacity in that family is what lets a part send work to a free machine instead of letting it wait when a machine is pulled for service. That, not the headline machine, is what protects a delivery date.
Pre-enquiry checklist
These are the items whose absence most often produces a quote that changes after review.
- 3D model in STEP or IGES, plus a 2D drawing — the drawing carries the tolerances the model does not.
- Material as a grade, not a family. "stainless" is not a specification; 316L is.
- Tolerance per feature, not a blanket note. A single tight dimension drives cost more than ten loose ones.
- Surface finish callouts where they matter, with the standard named (Ra in ISO or ASME).
- Quantity and expected repeat quantity. these are different numbers and they change the process.
What to confirm before the order
Before releasing, these are the items worth confirming in writing.
- Which drawing revision is being built — in writing, on the order acknowledgement.
- What the first-article report will contain, and whether it is full inspection or a sample plan.
- How capability is reported — the index, the stage, and the sigma estimator, named.
- Who owns an engineering change and how it is documented mid-run.
- Packaging, duty, and freight responsibility. whether the quote is EXW, FOB, or delivered.
What do the certificates actually cover?
Three certificates, each with a number you can check with the registrar:
| Standard | Certificate number | Scope note |
|---|---|---|
| ISO 9001:2015 | 116024/A/0001/UK/En | Quality management system |
| IATF 16949:2016 | 131941/A/0001/SM/En | Automotive QMS — excludes clause 8.3 product design |
| ISO 14001:2015 | 116024/B/0001/UK/En | Environmental management system |
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 plant manufactures to your design, it does not originate the design.
What tolerance applies?
±0.003 mm on CNC milling, ±0.002 mm on CNC turning; ±0.002 mm where precision grinding or wire EDM is used, set feature by feature when we quote.
What this shop actually runs
Capability evidence should come as specifics, not slogans. Behind this guide is a 6,800 m2 plant in Dongguan, China running 100+ CNC machines 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). Best 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). Best 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). Best 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). Best for shafts, bushings, flanges up to ±0.002 mm.
- Wire EDM (5+) - Sodick AQ535L (550/350/300 mm travel, ±20° taper, 800 kg workpiece). Best 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: ±0.003 mm CNC milling / ±0.002 mm CNC turning / ±0.002 mm grinding and wire EDM. Capability: Ppk >= 1.67 initial on key characteristics, Cpk >= 1.33 ongoing.
Certificates: ISO 9001:2015 (116024/A/0001/UK/En), IATF 16949:2016 (131941/A/0001/SM/En, with design clause 8.3 excluded, stated openly) and ISO 14001:2015 (116024/B/0001/UK/En), issued to Dongguan Zhuohang Ltd, registration 91441900MA4UWT6X39, founded 2005.
Where we ship: 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 — plus other countries and regions worldwide, shipped from our base in Dongguan, 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
Which markets do you export to?
In short, 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. Our service area also spans Europe, the Americas, Asia, Oceania and Africa — based in China, we serve customers worldwide.
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 a first-article inspection report?
A documented dimensional report on the first part off the process — typically per AIAG PPAP or a customer-defined format. It is the evidence that the process makes the drawing, and it is worth specifying before the order rather than after.
Is inspection documentation included in the quote?
It should be stated explicitly. A first-article report is a document someone has to produce, and whether it is a full dimensional report or a sample plan changes both the cost and what you receive.
How are parts packed for export?
Packing is chosen per part — finished faces bagged and boxed, steel corrosion-protected. Include it in the quote, since it changes the cost and how the parts arrive.
Can I audit the factory before placing an order?
Yes — on-site and video audits are both welcome at No. 8, Shuibian Songyuan Road, Hengli Town, Dongguan, Guangdong, China 523470.
Do you sign NDAs before reviewing drawings?
Yes — an NDA can be signed before any files change hands, and drawings stay inside the quoting system rather than circulating by email.
Continue reading: 4 Axis CNC Milling Checklist · 3 Axis CNC Milling
Standards referenced on this page
- ASTM A582/A582M-12 — Standard Specification for Free-Machining Stainless Steel Bars
- ISO 14001 — Environmental management systems — Requirements with guidance for use
- IATF 16949:2016 — Automotive quality management system standard