Custom Machined Parts

How do you know a manufacturer's traceability is real?

The test is whether the manufacturer can show the record on a real lot, not describe the system in general terms. This manufacturer's MES/ERP system records raw material, process parameters, machine data, batch, operator, and inspection per lot, and the chain can be pulled up on demand, for any part, in seconds. A manufacturer that can demonstrate the chain is running one; a manufacturer that can only talk about it is running a description.

When you ask to see the chain	A real system	A description
Raw material link	XRF result for the specific lot, on file	"We only use certified material"
Process link	Logged parameters per operation	"We follow strict process control"
Inspection link	CMM report tied to the lot	"We inspect every part"

How does traceability tie a part back to its origin?

The chain runs from the finished part all the way back to the raw material, link by link. The MES/ERP system records raw-material source and usage, process parameters, machine data, production batch, machining time, operator, and inspection results per lot, so any part can be traced to the exact machine, operator, and material lot that produced it.

Chain link	What the record shows
Raw material	Source, mill certificate, XRF verification
Process	Parameters, operation sequence
Machine	Which machine ran, its running data
Batch	Production batch, machining time
Operator	Who ran and inspected the part
Inspection	CMM results, pass/fail, SPC data

How does raw material enter the traceability chain?

The raw material is the first link, and it is verified before it enters the chain. Every incoming lot is XRF-checked against its mill certificate, so the material's identity is a measured fact, not a label taken on trust. That verification becomes the first entry in the traceability record, which is why the chain is trustworthy from its very first link.

Think of the raw material link as the part's birth certificate. Every other link in the chain hangs off it: the machine that cut it, the operator who ran it, the inspection that verified it. If the first link is a guess — "we think it is 6061" — then every link after it inherits the guess. The XRF check is what replaces the guess with a measurement, and it is the reason the rest of the chain can be trusted.

What tolerances does this manufacturer hold?

±0.003 mm on CNC milling, ±0.002 mm on CNC turning, and ±0.002 mm for precision grinding, verified on Hexagon CMMs with process capability Ppk ≥ 1.67 at the initial study on key characteristics and Cpk ≥ 1.33 on general characteristics. Capability is reported per characteristic: every report names the feature, its tolerance band, the sample size, the sigma method, and the study window. Each measurement is part of the traceability record — a dimension is not just held, it is held and logged, so the tolerance claim is backed by the chain.

Where the drawing does not call out a specific tolerance, general tolerances apply under ISO 2768, in fine (f), medium (m), or coarse (c) classes by nominal size. The distinction matters: the tight dimensions get CMM attention and a logged result, the loose ones get a general class that still has to be met. Both are part of the record, so a part is either in tolerance on every dimension or the record says where it is not.

Which materials does this manufacturer run?

Aluminum, stainless steel, carbon and alloy steel, brass, copper, titanium, and magnesium, plus engineering plastics. Every incoming lot is XRF-checked against its mill certificate, forming the first link in the traceability chain, so the material on the drawing is the material in the record, and the record is the material in the part.

Material	Typical role	What the chain confirms
6061-T6 / 7075-T6 aluminum	Housings, plates, brackets	Grade and temper match the drawing
304 / 316 stainless	Corrosion-duty parts	Grade — 316's molybdenum, not just "stainless"
4140 alloy steel	Shafts, gears, structural parts	Heat number and heat treatment
Brass / copper	Fittings, electrical parts	Alloy and conductivity grade
Titanium	High-value, weight-critical parts	Grade (2 vs 5) matches the spec

Does a single part carry the same traceability as a full run?

Yes. The MOQ is 1 piece, and a single part carries the same traceability record as a full production run — the chain is not reserved for volume. The discipline that isolates a bad lot runs on the first article exactly as it runs on the ten-thousandth, because the MES/ERP system records every lot without regard to size.

The single part is where the chain first proves itself. Your first prototype arrives with its own material, machine, operator, and inspection record, so the iteration loop is documented from day one. When you later scale to production, the record for the production lots chains back to the same process the prototype established.

How do you read a CMM report for a part?

A CMM report lists each called-out dimension, its nominal value, the measured value, and the deviation between the two. You read it by checking three things: that every critical dimension is actually measured, that the measured values sit inside tolerance, and that the report is tied to the specific lot you are holding. The report is the inspection link of the chain made visible — the same data the factory stores, printed and put in the box.

The value of a real CMM report over a pass/fail stamp is that it gives you the actual numbers. A stamp says "good"; a report says "this bore is 12.002 mm against a 12.000 ±0.005 callout." When you do your own incoming inspection, the report is the reference you compare your own measurements against, and the two together are how a defect gets caught at the dock instead of at your customer.

How does material property verification go beyond XRF?

XRF confirms the chemistry, that the alloy is what the certificate says. Some properties need more than chemistry: hardness confirms a heat treatment reached the part, and a tensile test confirms the mechanical properties the drawing expects. Micro-Vickers hardness and tensile testing cover those properties, and their results are logged to the same lot record as the XRF reading. So the material link is not just "the right alloy" but "the right alloy, in the right condition."

This matters for parts where the heat treatment is the point. A 4140 shaft that was machined but never quenched and tempered is a different part than one that was, and chemistry alone cannot tell them apart. The hardness reading can. The chain records both, so a part's material condition is a documented fact rather than an assumption.

What finishes can a part carry, and how are they logged?

A part's finish is part of its identity, and it is logged like any other property. Surface roughness is recorded as Ra in micrometers — Ra 3.2 for as-milled surfaces, Ra 1.6 for standard machined surfaces, Ra 0.8 for fine surfaces and sealing faces. Where a coating is applied — anodizing, plating, powder coat — the coating type and thickness are recorded, and the thickness is measured rather than assumed. The finish links in the chain are what make a part's surface verifiable.

The finish matters to traceability because a surface is where a part fails most often — corrosion, wear, and sealing all live at the surface. When a finish claim is challenged, the answer should be a logged roughness reading or a measured coating thickness, not a description of how the part "looks." The chain turns surface finish from an adjective into a number.

What certifications back this manufacturer?

ISO 9001:2015 (116024/A/0001/UK/En), IATF 16949:2016 (131941/A/0001/SM/En), and ISO 14001:2015 (116024/B/0001/UK/En). Certification matters for traceability because a certified system requires the record to exist and be auditable — the chain is not an optional extra, it is part of what the certificate verifies.

Honest scope note: IATF 16949 excludes product design under Clause 8.3 — this is a build-to-print manufacturer, which keeps the traceability unambiguous about who owns each link in the chain.

How do you verify a part matches the drawing at incoming inspection?

Your incoming inspection is the last checkpoint in the chain, and it has a simple checklist. Compare the CMM report to the drawing dimension by dimension. Confirm the material matches the mill certificate and the XRF reading. Confirm the lot number on the part, the box, and the packing list are the same. If all three align, the part and its record arrived together, and the chain is complete on your dock.

• Compare the CMM report to the drawing dimension by dimension, not just the headline tolerance.
• Confirm the material on the mill certificate matches the XRF reading and the drawing callout.
• Check the lot number on the part, the box, and the packing list are the same.
• Verify any finish callout — Ra or coating thickness — has a logged reading, not a description.

Incoming inspection is where the factory's chain becomes your record. A part that passes all four checks is a part you can put into your assembly without re-verifying its provenance, because the provenance arrived with it. That is the whole point of the chain — the record does the work once, at the source, and you verify rather than re-investigate.

What should you ask a manufacturer about its traceability?

Three questions separate a real chain from a description. How far back does the record go — to the raw material or only to the finished part? Is the record automatic or assembled on request? Can they pull up a real lot and show the chain from mill certificate to inspection? A manufacturer that answers all three with the record in front of them is one whose traceability you can file; one that hesitates is one whose chain is only as long as its marketing.

• Ask for the record on a lot you name, not a sample the manufacturer picks for you.
• Check the raw-material link shows an XRF result, not just a mill certificate number.
• Confirm the record is written as work happens, not assembled when you ask.
• Check the inspection link carries the CMM report, not just a pass/fail flag.

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