- 6,800 m² across two buildings in Hengli Town, Dongguan — production, inspection, and engineering under one roof.
- ISO 9001:2015 / IATF 16949:2016 / ISO 14001:2015 — certificate numbers published and verifiable.
- Stainless Steel: The defining machining problem is work hardening combined with low thermal conductivity.
- Grades in regular use: 303 for free-machining work, 304 and 316L for corrosion resistance, 17-4 PH where strength is needed after ageing, 416 and 420 where hardness is required.
- Incoming stock is verified against the mill certificate before it is cut.
Why stainless steel needs its own process
The defining machining problem is work hardening combined with low thermal conductivity. Heat does not leave with the chip, so it stays in the cutting zone; the surface layer work-hardens, and the next pass cuts through hardened material, which accelerates tool wear. The practical response is to keep the tool cutting rather than rubbing — maintain chip load, avoid dwelling, and do not take a finishing cut so light that it burnishes instead of shears.
Confirm the grade on the mill certificate by XRF before cutting — 304 and 316 look identical and behave differently in service.
Dimensional behaviour of stainless steel
Dimensional stability is good once the part has stopped moving, but thin walls distort from the residual stress released by removing stock. Stress-relieving between roughing and finishing is the standard response on a tight-tolerance thin-wall part.
The general rule for your part 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.
Surface treatment after machining stainless steel
Passivation after machining restores the chromium oxide layer that free iron from cutting tools has contaminated.
You specify finishing on the drawing, not assume it at the end. Where a coating adds thickness, threaded and press-fit features need the allowance stated, because a coating applied after inspection changes the fit.
What does stainless steel do to tooling and cycle time?
Heat does not leave with the chip, so it stays in the cutting zone; the surface layer work-hardens, and the next pass cuts through hardened material, which accelerates tool wear.
The lever that matters most for you is usually design rather than process: pocket depth, corner radius, and wall thickness change cycle time more than any tooling choice, because they determine the tool that can be used and therefore how much material can be removed per minute.
Three things that change the price without changing the part
The design levers on stainless are wall thickness and pocket depth. Thin walls distort as roughing releases residual stress, so a stress-relief operation and a separate finishing pass are usually cheaper than trying to hold a thin wall in one go. Avoiding a dwell. a tool rubbing rather than cutting, matters more here than on any other common material.
This is cheaper to settle at quote time than once parts already exist, because the changes are usually trivial on the drawing and significant on the machine.
What is the certification position?
ISO 9001:2015, IATF 16949:2016 (excluding clause 8.3 product design), and ISO 14001:2015, each with a certificate number verifiable with the registrar.
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, confirmed per feature at quote stage.
Choosing a grade within stainless steel
Austenitic, martensitic, and precipitation-hardening stainless grades are the grades that come up in practice. 303 for free-machining work, 304 and 316L for corrosion resistance, 17-4 PH where strength is needed after ageing, 416 and 420 where hardness is required.
Your grade selection is usually settled by the service environment, corrosion, strength, or temperature. And only then by machinability. If you choose on machinability first, your part meets the drawing and fails in service.
Which legal entity is actually responsible for the work?
Legally this is Dongguan Zhuohang Ltd, established 2005, Social Credit Code 91441900MA4UWT6X39, operating under the name Zhuohang Precision Machining Factory from No. 8, Shuibian Songyuan Road, Hengli Town, Dongguan, Guangdong, China 523470.
The 18-character code, checked against the National Enterprise Credit Information Publicity System, confirms a real manufacturer. A trading company may hold a business licence as well, but its scope is trading, not manufacturing, and its address is an office rather than a plant.
Depth in the relevant 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 waits in. The floor runs more than 100 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.
Having several machines in that family is what lets a part re-route rather than queue when a machine is pulled for service. That, not the headline machine, is what protects a delivery date.
What a Swiss machine does differently
A Swiss-style lathe feeds the bar through a guide bushing, so the cutting happens right at the support instead of along a long overhang. That is what lets it hold a tight tolerance on a long, thin part that would deflect and chatter on a conventional lathe. It is the process for small-diameter, high-aspect-ratio parts - pins, shafts, connectors, medical screws - where the ratio of length to diameter is what defeats an ordinary setup.
When to choose Swiss turning
Choose Swiss turning when the part is small in diameter and long in proportion, and the tolerance matters. It is not the cheapest way to make a short, fat part, and it is not the process for a part with a large head that does not fit through the guide bushing. If you know the length-to-diameter ratio, you choose correctly. This floor runs TSUGAMI B0206-III and B0205-III, STAR SR-32JII and SR-32J Type N, and Citizen Cincom A20-3F7 Swiss lathes at ±0.002 mm. Contact Felipe Iglesias at [email protected] or +86 13126536955 with the drawing.
How to verify the claim in one email
The fastest way to separate a real floor from a brochure is to ask for the machine list and the certificate numbers - and this facility answers in one email. Dongguan Zhuohang Ltd operates 100+ CNC machines across 6,800 m² in Hengli Town, Dongguan: Mazak VARIAXIS I-600 five-axis, INTEGREX I-250H S mill-turn, Brother SPEEDIO, and TSUGAMI, STAR and CITIZEN Swiss lathes. Inspection is on a Hexagon CMM with the 10:1 gauge rule, certification is to ISO 9001:2015, IATF 16949:2016 and ISO 14001:2015, and critical characteristics run at Ppk 1.67 initial and Cpk 1.33 in production.
Worldwide buyers across Europe, the Americas, Asia, Oceania and Africa are supplied from Dongguan. MOQ is 1 piece, lead times run roughly 3 / 7 / 30 days, and the quote from Felipe Iglesias ([email protected], +86 13126536955) comes back with the routing and the capability evidence together.
Take the next step
One drawing and one quantity is the whole hand-off. Send a STEP or IGES model and a 2D drawing with the tolerances, datums, material grade and finish, state the quantity and lead time, and the reply is an itemised quote - material, setup, cycle time, inspection - rather than a round number. If the drawing is incomplete, send what you have and the open questions; the point is to open the conversation, not to wait for a perfect package.
Contact Felipe Iglesias at [email protected] or +86 13126536955. MOQ is 1 piece, lead times run about 3 / 7 / 30 days, and the service area covers 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, shipped worldwide from Dongguan.
Tolerance and surface finish reference
±0.003 mm milled, ±0.002 mm turned, and ±0.002 mm ground or wire-cut, all verified on a Hexagon CMM against the datum scheme. Surface finishes span Ra 0.8 to 3.2 µm as-milled, Ra 0.2 to 0.4 µm ground, and Ra 0.05 to 0.1 µm polished. The 10:1 gauge rule governs every feature - the instrument must resolve ten times finer than the tolerance it checks. And the datum is what makes the tolerance real: read against two different datums, the same callout gives two different parts, so state the datum and the convention, ASME Y14.5 or ISO.
De-risking a first order
Start with a handful of parts to confirm the routing and the tolerance, then scale. The same machines, the same inspection bench and the same certificate numbers apply to a single piece and a production run alike, so a small first batch is the proof that a large one will hold the same numbers.
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). Aimed at 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). Aimed at 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). Aimed at 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). Aimed at shafts, bushings, flanges up to ±0.002 mm.
- Wire EDM (5+) - Sodick AQ535L (550/350/300 mm travel, ±20° taper, 800 kg workpiece). Aimed at 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.
Send a drawing and get a manufacturability read
Upload your model for a quote, or arrange a factory audit with [email protected] or +86 13126536955. Ask for Felipe Iglesias.
Frequently Asked Questions
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.
Do you certify stainless steel material?
Yes. Material certificates are supplied with the parts and incoming stock is checked against the mill certificate — composition by XRF, hardness where specified. Traceability is per heat or per batch as the certificate defines it.
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.
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.
Continue reading: 3 Axis CNC Swiss Turning · 4 Axis CNC Swiss Turning · 5 Axis CNC Swiss Turning
Standards referenced on this page
- ASTM A276/A276M-17 — Standard Specification for Stainless Steel Bars and Shapes
- ASTM A484/A484M-24 — Standard Specification for General Requirements for Stainless Steel Bars, Billets, and Forgings
- ISO 9001 — Quality management systems — Requirements