When to Use CNC Precision Machining
Ask for the registered name and the registration number. Ours is Dongguan Zhuohang Ltd, Social Credit Code 91441900MA4UWT6X39, verifiable in the National Enterprise Credit Information Publicity System.
A trading company can usually produce a licence too, but the scope will read as trading rather than manufacturing, and the address will be an office rather than a plant.
Step 2. Is there depth in the right machine 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 will wait in.
| Machine family | Count | Representative models | Role in the schedule |
|---|---|---|---|
| 3-axis vertical machining | 50+ centres | Brother SPEEDIO S500Z2N / S700Z2N | Prismatic work at the lowest cost per part |
| 4-axis machining | 20+ centres | Mazak VCE-430AL / VCE-570CL | Indexed multi-face parts without re-fixturing |
| 5-axis machining | 20+ centres | Mazak VARIAXIS i series | Single-setup complex geometry |
| 5-axis mill-turn | — | Mazak INTEGREX i-H series | Turned and milled features in one clamping |
| CNC turning / mill-turn | 25+ lathes | Mazak QT-COMPACT 200MSY L | Round parts, live tooling |
| Swiss-type turning | — | Citizen Cincom A20 / Star SR-32JII / Tsugami B0205 | Long, slender parts at high L/D ratios |
| Precision grinding | 7+ grinders | — | Final tolerance on bearing seats and roundness-critical faces |
| Wire EDM | — | Sodick | Sharp internal corners and hardened material |
Third check: inspection and capability reporting
Ask what instruments are on site and how capability is reported. A shop that quotes "Cpk 1.67" without naming the stage and the sigma estimator has not told you anything, VDA and AIAG use the same index names for opposite periods, so the label alone is ambiguous.
Step 4 — Who is accountable when something goes wrong?
Ask who signs off the first article, who owns an engineering change mid-production, and how a nonconforming part is handled and who pays. These are uncomfortable questions to ask and very cheap to ask early.
The contact who answers should be named and reachable. At this plant it is Felipe Iglesias, reachable at [email protected] or +86 13126536955. a person, not a form.
What design decisions move the cost on CNC precision machining?
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, established 2005).
How much capacity sits behind it?
a hundred-odd 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.
When CNC precision is the right answer, and when it is not
CNC precision machining is the right answer when four conditions are met: the tolerance band is ±0.05 mm or tighter (the part needs precision to function), the geometry is solid (cut from bar or plate, not bent or molded), the volume is 1-10,000 pieces (above 10,000 the process should move to a formed or molded process class), and the part is unique (not a catalog standard). Where CNC precision is the right answer: on a mating part (the part fits another part to ±0.003 mm), on a sealing surface (the part holds pressure to 0.025 mm flatness), on a locating feature (the part positions another part to ±0.003 mm), on a gear or shaft (the part transmits torque to ±5 µm pitch or ±0.002 mm diameter). Where CNC precision is the wrong answer: on a cosmetic part (±0.5 mm is fine), on a structural part with no precision features (±0.1 mm is fine), on a high-volume part (above 10,000 pieces, die casting or injection molding is cheaper). The hybrid strategy: precision-machine the functional features and accept the structural features at wider tolerance.
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.
When CNC precision is wrong — the alternatives matrix
Knowing when NOT to specify CNC precision is as important as knowing when to specify it. The alternatives matrix: high-volume simple geometry (above 10,000 pieces of a flat part — use stamping or die casting at $0.10-0.50 per part vs CNC at $1-5); large thin-shell geometry (a housing under 3 mm wall — use sheet metal fabrication); complex internal geometry (a part with internal cavities — use investment casting plus machining); very high volume of a polymer part (above 10,000 pieces — use injection molding at $0.50-3.00 vs CNC at $5-15). The break-even: CNC machining wins on 1-10,000 pieces of solid geometry with precision features; stamping wins above 10,000 pieces of flat geometry; die casting wins above 10,000 pieces of complex geometry; injection molding wins above 10,000 pieces of polymer geometry.
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.
When CNC precision is wrong — the alternatives matrix
Knowing when NOT to specify CNC precision is as important as knowing when to specify it. The alternatives matrix: high-volume simple geometry (above 10,000 pieces of a flat part — use stamping or die casting at $0.10-0.50 per part vs CNC at $1-5); large thin-shell geometry (a housing under 3 mm wall — use sheet metal fabrication); complex internal geometry (a part with internal cavities — use investment casting plus machining); very high volume of a polymer part (above 10,000 pieces — use injection molding at $0.50-3.00 vs CNC at $5-15). The break-even: CNC machining wins on 1-10,000 pieces of solid geometry with precision features.
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.
Get a quote with the cost drivers named
Send your drawing to [email protected] or call +86 13126536955. We will tell you which tolerance or setup is driving the number, not just the number.
Frequently Asked Questions
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.
Should I audit before or after the first order?
Before, but the audit does not have to be travel. A video walk of the floor, a machine list, and a certificate check resolve most of the question at no cost.
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 agreed per feature during quoting rather than guessed from a single quoted figure.
What is the single most useful question to ask a supplier?
"How many machines do you have in the family that makes my part?" It is not on any website, it cannot be answered from stock photography, and it predicts delivery behaviour better than any certificate.
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.
Is inspection documentation included in the quote?
It should be stated explicitly. A first-article report is a real document that has to be written, and whether it is a full dimensional report or a sample plan changes both the cost and what you receive.
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
- ASTM B209/B209M-21 — Standard Specification for Aluminum-Alloy Sheet and Plate
- ISO 9001 — Quality management systems — Requirements
