Aero CNC Machining Service

Aero work starts with the alloy, not the geometry. Aluminum 7075 machines cleanly and gives high strength per kilogram, so it dominates brackets, ribs, and fittings. 6061-T6 is easier to weld and cheaper, which suits non-structural housings and test rigs. Titanium TC4 (Ti-6Al-4V) offers better temperature resistance but cuts roughly four to six times slower than aluminum and eats tooling, so it belongs on parts where the thermal load justifies the cost.

Nickel alloys such as Inconel are the opposite case. They hold strength at temperatures where aluminum has already lost most of it, which is why they appear in engine-adjacent hardware. They also work-harden quickly, so shallow depths of cut, sharp tooling, and generous coolant flow are not optional. We machine Inconel on rigid 5-axis platforms with high-pressure coolant rather than on lighter machines.

Carbon fiber and other composites change the problem again. The fibers are abrasive and the resin can delaminate if the tool pushes instead of shears. That means diamond-coated cutters, controlled feed per tooth, and dust extraction at the cut point. If a drawing mixes composite panels with machined metal inserts, plan the sequence so the metal work happens before the composite is bonded, not after.

• 1
  Aluminum 6061 / 7075Fast to cut, good strength-to-weight, the default for structural brackets.
• 2
  Titanium TC4High temperature strength; slow cutting, higher tool wear, higher cost.
• 3
  InconelHot-section hardware; work-hardens, needs rigid setups and coolant.
• 4
  Carbon fiberAbrasive and delamination-prone; use diamond tooling and extraction.

Many aero features are not reachable in one orientation. Angled bosses, contoured pockets, and bolt-hole patterns on curved flanges all force a three-axis machine into multiple re-fixturings. Each re-fixture adds a datum shift. On a part with a ±0.005 mm tolerance stack, that shift can consume the entire budget before a single chip is cut.

Simultaneous 5-axis machining solves this by keeping the tool normal to the surface and reaching the feature without releasing the part. We run 16 simultaneous 5-axis machining centers with a Ø400 mm rotary table, which covers most airframe brackets and housings. Travel options include 750 × 1,150 × 550 mm and 600 × 600 × 600 mm envelopes, plus a 4,000 × 400 × 150 mm platform for long, slender parts such as stringers and rails.

Not every part needs five axes. Flat plates with through-holes and simple profiles are cheaper on a three-axis mill, and we keep 27 of them for exactly that work. The judgment call is whether the feature geometry forces multiple setups. If it does, five-axis is usually the lower-risk route even when the per-hour rate is higher.

Aero design pushes toward thin walls to save weight. The machining problem is that a thin wall deflects under cutting force, then springs back and leaves a tapered surface. Tool pressure also induces residual stress that moves the part after it is unclamped, so a dimension that measures correctly on the machine can drift out of tolerance overnight.

We handle this with shorter, more rigid tools held at effective angles, which keeps radial deflection low. Light depths of cut and higher spindle speeds remove material with less force per pass. Where a wall is very thin, we leave a controlled allowance and take a finishing pass after the part has relaxed. On some parts, a stress-relief step between roughing and finishing is the difference between holding tolerance and chasing it.

Fixturing matters as much as the cutter. Vacuum plates and low-melt holding compounds support the wall from behind instead of clamping it. For parts with a large open face, we sometimes machine a soft jaw that matches the contour, so the clamping load spreads over the whole surface rather than a few points.

Our general machining tolerance is ±0.005 mm (±0.0002 in) on critical features. That is a real number, not a marketing figure, and it applies to features that are reachable and stable in the setup. Tightening a non-critical dimension to the same value adds inspection time and cost without improving function.

Surface finish follows the same logic. As-machined surfaces run Ra 1.6–3.2 μm, which is fine for most internal brackets. Sealing faces and bearing bores often call for Ra 0.8–1.6 μm, and a few fluid-contact or optical surfaces need Ra 0.2–0.8 μm. If a drawing calls for a fine finish over a large area, expect more finishing passes and a longer cycle.

Threads, hole callouts, and edge breaks deserve attention before release. A 0.3 mm edge break on a thin titanium rib is not cosmetic; it removes a stress riser. On the other hand, specifying a tight positional tolerance on every hole in a pattern is usually unnecessary. Identify the holes that locate the part and let the rest follow the general tolerance block.

• 1
  General tolerance±0.005 mm on reachable, stable features.
• 2
  Standard finishRa 1.6–3.2 μm as machined, suitable for most internal parts.
• 3
  Fine finishRa 0.2–0.8 μm for sealing and fluid-contact surfaces.
• 4
  Edge breaksSpecify on thin ribs and fatigue-critical edges to remove stress risers.

A tolerance claim is only as good as the inspection behind it. Every part we ship goes through 100% inspection: incoming raw material check, in-process monitoring during cutting, and a final dimensional inspection before packing. Inspection reports are available on request, and we can supply first-article documentation for new programs.

For aero work, traceability usually matters as much as the dimension. Material certificates, heat lot numbers, and process records should travel with the part. If your quality system requires PPAP-style documentation or specific report formats, say so at quoting stage so the paperwork is planned into the job rather than added afterward.

Our quality system is certified to ISO 9001:2015, IATF 16949:2016, ISO 13485:2016, and ISO 27001:2022. The information security certification matters when drawings and models are exchanged digitally. Uploads are handled as confidential, and we sign NDAs on request.

Ask what machines the shop actually owns, not what it can broker. A supplier with no five-axis capacity will sub-contract your part, and that adds a handoff where tolerance and schedule control weaken. We run 127 high-precision CNC machines across three wholly-owned plants in Dongguan and Singapore, with 16 five-axis centers, 12 four-axis mills, 16 mill-turn centers, and 27 three-axis machines. That mix matters because it lets us route each feature to the right platform.

Ask how inspection is done and who signs the report. A shop that inspects only the first article and then ships the rest on trust is a different risk profile from one that checks every part. Ask about material certification and whether heat lot records are kept.

Finally, ask about communication during the job. A first-article photo and a dimensional report before the run continues will catch problems earlier than a finished shipment. We quote and return free DFM analysis within 12 hours, and production can start within 24 hours of approval. There is no minimum order quantity, so a single prototype and a 10,000-part run go through the same process.