Automotive production traceability — the IATF 16949 chain from melt to ship
Automotive traceability is the chain that links the finished part on the assembly line back to the billet it was cut from, and IATF 16949 is the system that enforces the chain. A part that arrives at the OEM without traceability is a part that the OEM cannot recall, and a part that cannot be recalled is a part that cannot be in an automotive program. The chain is not a single document; it is a series of records, each linking to the next, from the material certificate to the heat treatment record to the inspection report to the shipping record.
The chain runs forward and backward. Forward: the billet has a melt number, the bar stock has a heat number, the machined part has a routing number, the inspected part has a CMM report number, and the shipped part has a batch number. Each number links to the next, so a part found at the OEM with a defect is traced back to its batch, its inspection report, its routing, its heat, and its melt. Backward: a defect in a melt is traced forward to every part cut from that heat, and the parts are recalled. The IATF 16949 system enforces the record-keeping that makes both directions possible, and the facility behind this guide runs that system on a 100+ machine floor.
The practical records are the ones you see. The material certificate from the mill carries the heat number and the chemistry. The incoming inspection verifies the certificate against the bar, with XRF or spectrometry. The routing identifies the machine, the fixture, the operator, and the inspection at each step. The CMM report carries the dimensional result against the drawing band, with Ppk ≥ 1.67 initial and Cpk ≥ 1.33 in production on key characteristics. The control plan is the inspection routing that runs on every batch. The shipping record carries the batch number, the quantity, and the destination, and your receipt acknowledges the batch.
your move is to ask for the traceability chain at the quote stage, not just the inspection report, but the full set of records that link the part to the melt. A shop that runs IATF 16949 has the chain; a shop that runs ISO 9001 alone has the inspection report but may not have the heat-to-part link. The facility behind this guide holds both — IATF 16949:2016 (131941/A/0001/SM/En, design clause 8.3 excluded) and ISO 9001:2015 (116024/A/0001/UK/En) — and runs the chain on Hexagon CMM with ±0.003 mm milling and ±0.002 mm turning and grinding bands. Contact Felipe Iglesias at [email protected] or +86 13126536955 to set the traceability requirements before the first order.
The shop behind this automotive guide — IATF 16949 traceability chain in place
Backing this guide is a 6,800 m² plant at No. 8, Shuibian Songyuan Road, Hengli Town, Dongguan, Guangdong, China 523470, running 100+ CNC machines — Mazak VARIAXIS I-600 and INTEGREX I-250H S, TSUGAMI B0206-III/B0205-III, STAR SR-32JII / SR-32J Type N, Citizen Cincom A20-3F7 — plus 3-, 4- and 5-axis milling and turning, 5+ wire EDM and a Hexagon CMM bench with 20+ gauges.
Milling holds ±0.003 mm, turning ±0.002 mm, and grinding or wire EDM ±0.002 mm, all checked on a Hexagon CMM with the 10:1 gauge rule applied to every feature. Capability: Ppk ≥ 1.67 initial and Cpk ≥ 1.33 in production on key characteristics. Certified to ISO 9001:2015 (116024/A/0001/UK/En), IATF 16949:2016 (131941/A/0001/SM/En, design clause 8.3 excluded, openly disclosed) and ISO 14001:2015 (116024/B/0001/UK/En), held by Dongguan Zhuohang Ltd, USCC 91441900MA4UWT6X39, established 2005. Customers across 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 are supplied from China, worldwide. Contact Felipe Iglesias at [email protected] or +86 13126536955 to begin the quote, and ask for the certificate numbers, the machine list and a past CMM report together.
- Dongguan Zhuohang Ltd (Registration No. 91441900MA4UWT6X39), operating as Zhuohang Precision Machining Factory, established 2005.
- a hundred-odd machines including 20+ 5-axis centres; 100+ staff, 80%+ skilled technicians.
- Whether the supply relationship survives a change in volume or specification, A supplier with one machine in the relevant family has a single point of failure.
- Build-to-print: we machine to your drawing and report back to it.
What does "supplier" actually commit a supplier to?
The question to ask a supplier is not what it can make today but what happens when the order doubles, or when the drawing changes at revision C. Capacity questions are really questions about queue structure: how many machines sit in the family that makes your part, and how much of their time is already committed.
A supplier with one machine in the relevant family has a single point of failure. 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.
Ask what share of the machine hours in your part's family is already committed. It is an unusual question and a revealing one: a supplier that cannot answer it does not know its own queue, which means the date it gave you was an estimate rather than a schedule.
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, fixed for each feature at the quote.
Where the money is actually decided
For a repeat part, the lever is stability rather than price: hold the revision, hold the material source, and hold the process. A supplier can usually improve a repeat part's cost once the process is settled, but only if the drawing has not moved.
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 identifies the legal entity behind the machines?
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.
What capacity actually sits behind the claim?
Capacity is depth, not a headline machine. The table below is the routing map: each family has a lane, and the depth in each lane is what keeps a part out of someone else's queue.
| 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 |
What to read out of this list: a part does not wait behind a single machine. Depth in the same family is what lets work move to another lane rather than sit in a queue, and it is what makes a prototype ramp to production on the same floor.
How to verify a China CNC machining supplier in an afternoon
Whether you buy from this plant or another, these checks separate a real floor from a brochure. None of them require a purchase order.
- Machine count in the specific family your part needs? Ask for it in writing.
- Second-source arrangement for outside processes? Ask for it in writing.
- How engineering changes are handled mid-production? Ask for it in writing.
- What happens to your slot when a larger customer expands? Ask for it in writing.
What happens between quote and first article?
Programming and offline verification, fixture design and build, material inward inspection, roughing, finishing, inspection, and the first-article report. Each stage has a way to fail, and the costly failures sit at the start and the end. 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, cuts cycle time more than any change of machine, because it changes the tool that can be used.
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). Made 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). Made 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). Made 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). Made for shafts, bushings, flanges up to ±0.002 mm.
- Wire EDM (5+) - Sodick AQ535L (550/350/300 mm travel, ±20° taper, 800 kg workpiece). Made 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.
- Automotive routing - Brother M300X3 RD / M200X3 RD for EV motor housings and wheel bearings; SPEEDIO S500Z2N / S700Z2N for cylinder heads and crankcases; QT-COMPACT 200MSY L for shafts.
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.
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
Do you hold stock or consignment for repeat orders?
Repeat orders can run against a forecast so stock and, where the part warrants it, dedicated fixturing are held ready. This is a commercial arrangement, not a standard term, so raise it at the second order rather than the first.
Is your IATF 16949 certificate valid for design work?
No. The certificate excludes clause 8.3 (product design). The plant is certified to manufacture to your design and to run the associated process controls, not to originate product design.
How quickly can you quote China cnc machining?
Quotes are returned with a manufacturability read rather than a price alone — where a tolerance or a feature will drive cost, that is flagged at quote stage rather than after the first article. Turnaround depends on drawing completeness.
What files do you need for a quote?
In short, A 3D model (STEP or IGES) with a 2D drawing carrying the tolerances, surface finish callouts, material spec and any inspection or certification requirements. The drawing defines the contract — the model alone usually leaves the tolerance scheme unspecified.
How is an engineering change handled mid-production?
The change is documented against a revision, the affected parts in process are identified, and the revised drawing is confirmed in writing before work restarts. The important part is that the revision in force at any moment is a single, written one.
How is material traceability maintained?
Incoming stock is checked against the mill certificate — composition by XRF, hardness where specified — and traceability is held per heat or per batch as the certificate defines it.
Are you a manufacturer or a trading company?
A manufacturer. The legal entity is Dongguan Zhuohang Ltd (Registration No. 91441900MA4UWT6X39), operating a 6,800 m² facility with a floor of 100-plus machines and 100+ staff in Dongguan. Factory visits are welcome.
Continue reading: Automotive China CNC Machining · China CNC Machining for Aerospace · China CNC Machining for Defense
Standards referenced on this page
- IATF 16949:2016 — Automotive quality management system standard
- ASTM A582/A582M-12 — Standard Specification for Free-Machining Stainless Steel Bars
- ASTM A484/A484M-24 — Standard Specification for General Requirements for Stainless Steel Bars, Billets, and Forgings