Custom Machined Part Services

How does each service leave a traceability record?

Every operation — milling, turning, mill-turn, grinding — is logged to the MES/ERP system with its process parameters, machine data, operator, and machining time. The record is written as the work happens, not reconstructed later, so the finished part carries the full chain of every service that touched it. When you ask where a part came from, the answer is a sequence of logged operations, not a memory.

Service	What it writes to the record	Why it matters for the chain
Milling	Program, speeds and feeds, machine ID, operator	Pinpoints which setup produced a feature
Turning	Tool offsets, machine ID, operator, cycle time	Separates a turning fault from a later operation
Mill-turn	Single-setup sequence, machine ID	Removes a hand-off gap inside one machine
Grinding	Wheel, pass counts, finish reading	Links the final tolerance to its operation

Which services run in-house?

The metal-cutting core runs in one 6,800 m² facility, which is what keeps the traceability chain unbroken. Every operation stays inside the same MES/ERP record, so a part that moves from one machine to the next carries its record with it.

Service	Capacity	Max workpiece
CNC milling (3-axis)	50+ centers	1300 × 700 × 600 mm
CNC milling (4-axis)	20+ centers
CNC milling (5-axis)	20+ centers
CNC turning	25+ lathes	Ø720 × 1280 mm
Mill-turn	Multi-task centers	Single-setup complex geometry
Precision grinding	7+ (surface / centerless / cylindrical)	±0.002 mm finishes

How does milling log its link in the chain?

Milling is where most prismatic parts — housings, brackets, plates, manifolds — get their shape, and it writes the richest record of the cutting process. The program number, the speeds and feeds, the machine ID, and the operator are logged per operation, so a feature that goes out of tolerance can be traced to the specific setup that cut it. On a Mazak or Brother machining center, the controller reports what actually ran, not what was supposed to run, which is what makes the milling link a record rather than a recollection.

From a traceability standpoint, milling matters because it is often the first operation that turns raw stock into geometry. The milling link is where the part's identity is first cut into it, and it becomes the anchor the later links attach to. A clean milling record means the downstream record has a solid place to start.

How does turning log its link in the chain?

Turning produces the round parts — shafts, pins, bushings, sleeves — and logs the tool offsets, machine ID, operator, and cycle time for each operation. The tool offset is the telling entry: it records how the cutting edge was positioned against the stock, which is exactly the number that drifts as an insert wears. When a turned diameter goes out of tolerance, the turning record tells you whether the offset was wrong, the tool was worn, or the machine was the source.

Turning on Citizen or Star lathes in addition to the core fleet gives the record the same continuity for bar-fed and small-diameter work. The service matters to traceability because round parts often carry the tightest fits — a bearing seat or a press fit — and those are the dimensions where a few microns of drift is the difference between a part that assembles and one that does not. The turning record is where that drift is caught and logged.

How does mill-turn close the hand-off gap?

Mill-turn machines combine turning and milling in a single setup, and they matter to traceability for a specific reason: they remove the hand-off. A complex part that would otherwise travel from a lathe to a mill — losing its record at the boundary between two machines — stays on one machine under one record. The single-setup sequence is logged once, and there is no gap where a chain could break.

That is the real value of mill-turn for a traceability-minded buyer. The fewer hand-offs a part goes through, the fewer places the record has to survive a transition. Mill-turn compresses two or three operations into one logged sequence, which shortens the chain and removes its weakest links at the same time. For parts with turning and milling features on the same workpiece, it is the cleanest record available.

How does grinding log the final tolerance?

Grinding is where the tightest tolerances are held — ±0.002 mm — and it logs the wheel, the pass counts, and the finish reading. These entries are the difference between a part that was "finished" and a part that was finished to a measured value. The wheel identity and pass counts record how the surface was produced; the finish reading records the Ra the process actually achieved.

Grinding matters to the chain because it is the last machining operation on the tightest surfaces, and it is where the final tolerance claim is either made or broken. When a bearing seat has to run true to ±0.002 mm, the grinding record is the evidence that it does. Without it, the tolerance is a claim on the drawing; with it, the tolerance is a logged fact in the chain.

How does the traceability chain stay unbroken across services?

The chain stays unbroken because all four services run in one facility under one MES/ERP system. The record follows the part from operation to operation — turning to milling to grinding — without a hand-off that would break the chain. A hand-off to another shop is exactly where traceability fails, because the second shop has its own system and the link between the two is a gap. Keeping the services in-house keeps the chain continuous.

The practical test is whether the record survives a multi-process part. A part that needs three services should come back with one record that shows all three, in order, each with its machine, operator, and parameters. That is what in-house services deliver, and it is what you should ask to see before trusting that a chain is unbroken.

How is inspection logged to the chain?

Inspection is the last link, and it closes the record. CMM measurements, pass/fail results, and SPC data are recorded to the same MES/ERP system per lot, so the chain ends with the verified part, not with the machined blank. The inspection record is what turns a chain of operations into a chain of evidence.

The inspection link is also where the record becomes useful to you, the buyer. When you receive a part, the CMM report that ships with it is the inspection link made visible — the same data the factory holds in its chain, printed and put in the box. It is the proof that the tolerance on the drawing was the tolerance on the part, and it is yours to file against your own incoming inspection.

What workpiece sizes can you machine?

Milling handles workpieces up to 1300 × 700 × 600 mm, and turning up to Ø720 × 1280 mm. Size does not change the traceability: each operation on a large part is logged exactly as it is on a small one, so the record is complete regardless of the part's dimensions. A large housing is as traceable as a small pin.

Do you take single-part and low-volume work?

Yes. The MOQ is 1 piece, and a single part carries the same traceability record as a full run. The chain is not reserved for production volume — it logs every lot, including the first article, so the validation part is as traceable as the ten-thousandth.

This matters because the first part is the one you learn from. It carries its own full record, so when you iterate on the design, the changes and the baseline are both documented. You are not paying for volume to get the record; the record comes with the single part.

Which materials run through which service?

The material link is the same regardless of service, because every lot is XRF-verified at the door before it reaches any machine. What changes is which service the material spends most of its time in. Aluminum parts lean milling; shafts and pins lean turning; tight bearing surfaces lean grinding. The chain does not care — the material link is written once, at the door, and every service that follows reads from it.

Material family	Primary service	Why
Aluminum (6061, 7075, 5052)	Milling	Cuts fast; housings and plates
Stainless (304, 316)	Turning / milling	Round and prismatic parts, corrosion duty
Alloy steel (4140)	Turning then grinding	Shafts that need a ground finish
Brass / copper	Turning	Fittings, electrical and thermal parts
Titanium	Milling / turning	Slow cutting, high-value parts

What should you confirm in a services agreement about traceability?

Confirm three things in writing: that every operation is logged to the record, that the record follows the part across services without a hand-off gap, and that inspection results are recorded per lot. A supplier that answers all three is one whose services leave a real trail; one that hedges is one whose chain has a gap somewhere.

• Confirm every operation logs its parameters, machine, operator, and time to the record.
• Confirm the record follows the part across milling, turning, and grinding without a hand-off gap.
• Confirm inspection results — CMM, pass/fail, SPC — are recorded per lot, not per order.
• Ask to see the chain for a real multi-process part, from raw material to shipped piece.

Send a drawing and the shop will show you the traceability record on a real multi-process part — every service logged, from material to inspection.

How does the record follow a part through a design change?

A design change is where a part gets a new identity, and the chain has to follow the revision. When a drawing moves from revision A to revision B, the new revision is released as its own part record, so a lot of B parts is never confused with a lot of A parts. The first article for the new revision is logged fresh, and the chain records which revision each lot was machined against. That is what keeps a change from turning two different parts into one ambiguous record.

For you, this is the difference between a supplier that manages revisions and one that mixes them. Ask how a revision change is handled: the answer should be that each revision gets its own record and its own first article, so a part you receive can be tied back to the exact drawing revision it was built to. That link is part of the chain, and it is the link that prevents an old-revision part from slipping into a new-revision assembly.

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). Typical work: 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). Typical work: 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). Typical work: 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). Typical work: shafts, bushings, flanges up to ±0.002 mm.
• Wire EDM (5+) - Sodick AQ535L (550/350/300 mm travel, ±20° taper, 800 kg workpiece). Typical work: 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.

Frequently Asked Questions

Standards referenced on this page

• ASTM B211/B211M-19 — Standard Specification for Aluminum-Alloy Rolled or Cold Finished Bar, Rod, and Wire
• ASTM A276/A276M-17 — Standard Specification for Stainless Steel Bars and Shapes
• ISO 9001 — Quality management systems — Requirements