Aerospace CNC Machining in China: Precision You Can Audit

Aerospace · CNC Machining Aerospace CNC Machining in China: Precision You Can Audit Brackets, housings, structural and turbine-adjacent components in titanium, 7075 and Inconel, machined to ±0.005 mm with lot-level traceability. One supplier for the metal and the board. Request a quoteSee capabilities What aerospace CNC machining actually demands Aerospace machined parts sit in a different risk class than industrial hardware. A 0.02 mm step on a consumer bracket is a cosmetic note; the same step on a landing-gear bracket can change a load path. Three things define the category: function-critical geometry, a material whose pedigree must be provable, and every feature measurable after the fact. We treat aerospace work as a documentation problem first and a machining problem second — the part is only as good as the record that proves it. The reader here is usually an engineer or a sourcing manager who has been burned by a shop that quoted a tolerance it could not hold, or shipped a part with no way to trace the alloy. That is exactly the failure we design against. What follows is what we machine, how we hold it, what we are certified to — and just as important, what we are not. Aerospace part types we machine Aerospace CNC work breaks into four categories, each with its own geometry, material and paperwork profile. If a part sits between two categories, its machining and record-keeping follow the stricter of the two. Brackets and mounts Avionics brackets, sensor mounts, actuator brackets, line-clamp and harness supports. These are usually aluminum 7075 or 17-4 PH stainless, machined to tight true-position and flatness callouts so a box bolts down without stress and a sensor points where the drawing says it points. The critical features are hole patterns, mounting faces and thin-wall stiffness. Brackets are high-mix, often revised, and usually needed in low volume first — which is why the no-MOQ policy matters more here than on any other part class. Housings and enclosures Electronic housings, connector shells, pressure housings, instrument bodies and actuator cases. Material follows environment: aluminum for weight and shielding, stainless for corrosion, titanium where both weight and strength matter. Sealing surfaces, boss locations, lens apertures and O-ring grooves are the critical features. Many ship with the electronics we also build, so the housing and the board come from one supplier under one traceability record. Turbine-adjacent and hot-section components Be precise about scope here, because honesty matters on the hot side. We machine non-rotating, bar-and-plate components — seal rings, nozzle housings, shroud segments, valve bodies and instrumentation bosses — in Inconel and other nickel alloys. Rotating airfoils, discs and blisks are forging-and-grinding work that belongs in a dedicated aerospace forge-and-finish shop, and we say so rather than claim it. What we deliver is the machined-from-bar hot-section hardware where tolerances are tight, the alloy is unforgiving and the record is everything. Structural components Ribs, spars, fittings, longeron brackets and small load-bearing links machined from plate or bar in 7075 or titanium. These carry load, so grain direction, edge condition and surface finish matter as much as dimension. We manage corner radii, edge break and finish to spec, and we hold the dimensional callouts the drawing demands. Structural work favors 5-axis and long-reach setups, which the Mazak machining centers on the floor handle without re-fixturing a part three times. Aerospace materials: titanium, 7075, Inconel Material choice is an engineering decision, not a preference, and it is never our call to substitute. Every bar is XRF-verified against its mill certificate before it reaches a spindle — no wrong alloy, no guessed grade. The three families below cover most programs we run. For alloy chemistry and heat-treat detail, the ASM Handbook remains the standard reference (ASM International). Titanium (Ti-6Al-4V, Grade 5) Titanium earns its place on strength-to-weight and corrosion resistance. It is abrasive to tooling, holds heat at the cut and work-hardens if you let the tool dwell — so feeds, speeds and coolant strategy are set deliberately, not improvised. We run Grade 5 routinely for brackets, housings and structural fittings where every gram counts. The same discipline that keeps titanium from smoking a tool is what keeps its tolerances repeatable. Aluminum 7075 This is the aerospace structural aluminum: high strength, low weight, machinable fast. The trade-off is corrosion and stress-corrosion sensitivity, which is why the temper (T6 versus T7351) and the post-machining finish — anodize or a conversion coating — are specified on the drawing and locked, not assumed. We machine 7075 for ribs, brackets, housings and fittings, and we respect the temper callout rather than treating it as a suggestion. Inconel and nickel superalloys Inconel 718 and 625 are chosen where a part lives at temperature or in a corrosive stream and aluminum would soften and steel would creep. They are slow to machine and hard on tools; they work-harden aggressively and punish an over-aggressive cut. The payoff is a part that holds its shape where it matters. We run nickel alloys for hot-section-adjacent hardware, and we quote them realistically — the cycle time is what it is, and pretending otherwise only produces late parts. AlloyCommon grade / specWhy aerospace uses itMachining note Titanium Ti-6Al-4VGrade 5, AMS 4928Strength-to-weight, corrosion, temperature toleranceAbrasive; work-hardens; needs deliberate feeds and coolant Aluminum 70757075-T6, AMS 4045 / T7351, AMS 4049High strength-to-weight for structural, non-elevated temperatureMachines fast; respect temper and stress-relief; finish per spec Inconel 718 / 625AMS 5662 / 5666Hot-section strength, creep and corrosion resistanceWork-hardens aggressively; slow feeds; heavy tool wear 17-4 PH stainlessAMS 5643Corrosion plus hardness for fasteners, fittings and bracketsHeat-treat after machining; passivate to restore oxide layer Tolerances and GD&T For a quality lead. Aerospace drawings arrive dense with GD&T — true position on hole patterns, concentricity on bores, profile on sealing faces, flatness on mounting pads. We machine to the frame and the datums, not just to the numbers. A dimension held to size but off datum is a rejected part; we read the drawing the way the engineer wrote it. The capability we quote is what the floor actually holds. Milling and turning hold ±0.005 mm on critical features; grinding and wire EDM hold ±0.002 mm for bearing seats, seal surfaces and tight profiles. The internal standard is Cpk ≥ 1.67 on key characteristics and ≥ 1.33 on general features, with SPC on critical dimensions across the run. Critical characteristics are held to Cpk ≥ 1.67 under SPC, general features to Cpk ≥ 1.33. The proof is in the measurement, not the claim. Critical features are checked on a CMM against the datum scheme, bores on calibrated bore gauges and finishes on roughness testers, with the results written into the first-article and SPC records rather than summarized in a sales slide. That is what turns a tolerance callout from a promise into a repeatable part — and it is the record your quality file leans on when the audit lands. ProcessHeld toleranceTypical aerospace features Milling / turning±0.005 mmBores, bosses, sealing surfaces, true-position hole patterns Grinding±0.002 mmBearing seats, seal rings, close-tolerance OD/ID Wire EDM±0.002 mmTight profiles, slots, features a cutter cannot reach Surface finish and edge quality On a loaded part, a rough surface or a sharp corner is a crack-initiation site, not a cosmetic detail. Aerospace finish work is about fatigue and fit: a sealing face that leaks, a thread that galls, or a machined edge that starts a crack in service is a failure the drawing was written to prevent. We match finish and edge condition to the spec — Ra callouts measured on roughness testers, edges deburred and broken to the radius the drawing requires, and coatings applied to specification rather than to convenience. Surface finish on aerospace parts is inseparable from material. Stainless and 17-4 get passivation to restore the chromium oxide layer; aluminum gets anodize or conversion coating per the drawing; titanium gets the finish the spec calls for, without shortcuts. The finish is a process step with its own control, not an afterthought applied to make a part look right in a photograph. Certification context: what we hold, and what we do not Be clear on this point, because it is where aerospace buyers get misled. Nex-G is certified to ISO 9001:2015 and IATF 16949:2016, and holds ISO 14001:2015. We are not certified to AS9100, and we do not hold NADCAP. We say this outright because a supplier that lets you assume AS9100 is a supplier you cannot trust with the parts that follow. What this means in practice: our aerospace work runs under ISO 9001 plus the traceability discipline we carry from the IATF 16949 automotive system — lot control, PFMEA, control plans, first-article and CMM records, SPC on critical features. That discipline is real and transferable, and for many non-flight-critical and ground-support components it is exactly what the program needs. What it is not is a substitute for AS9100 where your prime or your own QMS requires it. If a program demands AS9100 at the supplier tier, we will tell you before you release the drawing — not after the parts are late. The boundary is clean: we are a contract manufacturer. We machine to your specification; airworthiness, design authority and certification of the finished article sit with you, not with us. We contribute repeatable precision, honest documentation and the records your quality file can rely on — and we never overstate the certificate we hold. See the quality system. Honest about scopeNex-G holds ISO 9001, IATF 16949 and ISO 14001. We are not AS9100 or NADCAP certified. Aerospace programs run under ISO 9001 plus full lot-traceability and SPC discipline — so you can build your quality agreement on facts, not assumptions. Traceability and lot control For an aerospace buyer, traceability is the difference between a part you can defend in an audit and one you cannot. A machined component is only as good as the record that links it to its material, its process and its inspection data. We build that record by default. Every bar is XRF-verified against its mill certificate before it reaches a spindle, so the alloy lot is locked to the job — not assumed. The raw-material source, heat lot and certificate number travel on the job traveler and into the final record. If a lot is ever questioned, a finished part traces back to the specific bar it came from. The shop runs MES/ERP-linked, so each lot carries its machine, process parameters, operator, inspection results and ship date — a part made this year is still provable next year. First-article inspection and CMM reports cover the critical features on the drawing; SPC tracks those dimensions across the run. We document to your requirements — material certs, first-article, CMM report, lot traceability — because the record is part of the deliverable, not an option you have to request twice. See the quality system. DFM for aerospace machined parts For a manufacturing engineer. Design for manufacturability pays off fastest on aerospace parts, where tolerances and finishes are expensive and a redesign resets a validation clock. A few drawing-stage decisions remove most of the downstream risk. Apply tolerance where function demands Apply tight tolerances and fine finishes only to the features that carry function — sealing surfaces, datum faces, load paths, true-position hole patterns — and leave the rest at commercial tolerances. A drawing that over-specifies every feature raises cost without raising safety and makes the part harder to hold in SPC. Design for fatigue, not just for fit Avoid sharp internal corners, which concentrate stress and trap chips; specify a corner radius a standard tool can cut. Break edges on loaded parts to the radius the drawing requires, and keep thin walls consistent so a bracket does not sing during machining or crack in service. Lock the material and the temper Standardize on a stocked, well-documented alloy and lock the exact grade and temper on the drawing — 7075-T6 versus T7351, Ti-6Al-4V versus a softer grade, Inconel 718 versus 625. Any grade or temper change goes through your sign-off, never silently. The material is part of the design; leave it open and the shop is forced to guess. The complete DFM guide. The aerospace supplier audit checklist If you are qualifying a machining supplier for aerospace work — whether ground-support, structural or non-flight-critical hardware — a handful of checks separate a shop that can hold the work from one that can only quote it. Run them before you release a drawing and the later surprises become your problem instead of an audit finding. Audit areaWhat to confirmWhy it matters Material controlXRF verification against mill certs, lot locked to jobA wrong alloy or guessed grade is a structural failure, not a cosmetic one Tolerance evidenceLive SPC data and CMM reports, not a capabilities brochureA shop that holds ±0.005 mm can show you the Cpk, not just claim it TraceabilityPart-to-bar linkage, lot travel on the job travelerAn auditable record is the difference between a defense and an assumption Documentation setMaterial certs, first-article, CMM reports, SPC logsThe record is part of the deliverable, not an add-on you request twice Scope honestyExplicit AS9100 / NADCAP status, stated before quoteA supplier that lets you assume a certificate will mislead you elsewhere Two of those rows matter more than the rest. Material control and scope honesty are the ones that convert into a part that fails or a program that stalls, and both are checked in a five-minute conversation before any money moves. Ask for the certificate numbers and the SPC log, and watch how fast each one arrives. Why machine aerospace parts in China For a sourcing manager, the case for Chinese aerospace CNC is specific, not general: process capability and process discipline at a cost that lets you iterate. Nex-G runs 80+ CNC machines from Mazak, Brother, TSUGAMI and Sodick in a 6,800 m² Dongguan Hengli facility, holding ±0.005 mm on mill and turn and ±0.002 mm on grind and wire EDM — flight-relevant capability, not commodity bracket work. The second argument is iteration speed. With no MOQ and lead times of 3, 7 or 30 days by complexity, you can order a handful of design-iteration parts without committing to a production run — important when a design change resets a qualification clock. The third is consolidation: because we also build the electronics, a housing or bracket that carries a board ships as one assembly from one supplier, under one traceability record. The honest caveat: China is a cost and capability decision, not a certification shortcut. We machine to your specification and you own airworthiness, design and certification. The value we add is repeatable precision, real documentation and the capacity to scale — not a certificate we cannot show you. What actually drives aerospace part cost and lead time For a sourcing engineer. Aerospace parts cost more than commercial work for reasons you can name, and naming them is what lets you reduce them at the drawing. The big drivers are the material, the tolerance and finish, and the documentation. Material. Titanium and Inconel cost multiples of 6061 and machine far slower, so raw-material price and cycle time move together. Lock the exact grade and temper, but do not over-specify — 7075-T6 where T7351 is not needed still spends money. Tolerance and finish. Every feature held to ±0.005 mm or ground to ±0.002 mm adds an inspection step, and every anodize, passivation or plating line adds a process and its paperwork. Apply them only where function demands. Documentation. First-article, CMM reports and lot traceability are fixed costs per program, not per part — they hurt at five pieces and disappear into the run at five hundred. That is exactly why low-volume aerospace work favors a no-MOQ shop that already runs the paperwork as default. Volume. Aerospace is high-mix and low-volume by nature, so setup and inspection amortize poorly. The lever you control is design stability — every revision resets the first-article clock. The Nex-G anchor Nex-G is a Dongguan, China contract manufacturer operating from Hengli since 2006, with 6,800 m² of floor space and 100+ staff. The machining floor runs 80+ CNC machines — Mazak and Brother machining centers, TSUGAMI Swiss-type lathes, and Sodick wire EDM and grinding — supported by inspection including CMM, vision and XRF material verification. Capability summary: ±0.005 mm on milling and turning, ±0.002 mm on grinding and wire EDM; Cpk ≥ 1.67 on key characteristics and ≥ 1.33 on general features, with SPC on critical dimensions; no MOQ; lead times of 3, 7 or 30 days by complexity. Certifications are ISO 9001:2015 (116024/A/0001/UK/En), IATF 16949:2016 (131941/A/0001/SM/En, no design responsibility under clause 8.3) and ISO 14001:2015, registered through URS and current to 2027. We do not claim AS9100 or NADCAP. Send the STEP or IGES model and the 2D drawing with GD&T, the material and finish, and your volume and tolerance. We return a DFM note flagging the features that drive cost or risk failure, the achievable tolerance, and a lead time — and where we can, the specific change that cuts the part's cost. Tell us what “done” looks like on paper and we will quote to it. Request a quote → On the floor the checks are concrete rather than aspirational. Every BOM line is cross-checked against the drawing and the purchase spec before release, so a 7075 callout cannot silently become 6061. Critical alloys are bought through a cross-checked second source with a matching mill test certificate, and each incoming lot is confirmed by XRF / PMI before it reaches a machine. For aerospace programs we run FAI per AS9102 so the first article is dimensionally signed off before the run begins, and the lot traceability above ties every feature back to its heat number. Machining aerospace parts you can audit?Send the drawing with your tolerance and traceability requirements — we will confirm what we can hold and quote the metal and the electronics together.Request a quote Frequently asked questions What tolerance can you hold?±0.005 mm on milling and turning, ±0.002 mm on grinding and wire EDM. The internal standard is Cpk ≥ 1.67 on key characteristics and ≥ 1.33 on general features. Which aerospace materials do you machine?Titanium (Ti-6Al-4V), aluminum 7075, Inconel and other nickel alloys, and 17-4 PH stainless — all XRF-verified against mill certificates before machining. Are you AS9100 or NADCAP certified?No. Nex-G holds ISO 9001:2015, IATF 16949:2016 and ISO 14001:2015. Aerospace work runs under ISO 9001 plus full lot-traceability and SPC discipline, but we do not claim AS9100 or NADCAP — we state this before you release a drawing. Do you provide material and lot traceability?Yes. Every bar is XRF-verified against its mill certificate, and each lot carries its material source, process parameters, operator, inspection results and ship date — a finished part traces back to the bar it came from. What inspection do you perform?CMM and vision measurement on critical features, XRF material verification, and roughness measurement on finished surfaces. First-article and CMM reports are available on request. Can you machine and assemble with the electronics?Yes. Nex-G builds the electronics too, so a housing or bracket that carries a board ships as one assembly from one supplier under one traceability record. What is your minimum order quantity?No MOQ. We run single-piece prototypes through to production; lead times are 3, 7 or 30 days depending on complexity and process steps. How do you verify the material is correct?Every bar is XRF-verified against its mill certificate before it reaches a spindle, so the alloy lot is locked to the job rather than assumed. Do you handle low-volume and prototype aerospace work?Yes — there is no MOQ, and lead times run 3, 7 or 30 days by complexity. A handful of design-iteration parts carries the same traceability and documentation discipline as the production run. What documentation ships with each aerospace lot?Material certs, first-article and CMM reports, and lot-traceability records, plus SPC data on critical dimensions. The record is part of the deliverable — not an option you have to request twice. Related articlesMedical Device CNC Machining in Titanium5-Axis CNC Machining GuideCNC Machining Tolerances