Buyer Decision Guide
How to Choose a CNC Machine Shop for Aerospace Work
Aerospace CNC work is quality-management heavy. AS9100 lineage, ITAR compliance, extensive documentation, tight tolerances on structural and engine components — the requirements are different from oilfield. This guide is how a buyer evaluates a shop for aerospace-grade precision work.
AS9100 — the aerospace QMS baseline
AS9100 is the aerospace industry's quality-management standard. Built on ISO 9001 with additional aerospace-specific requirements: risk management, product safety, counterfeit-parts prevention, first-article inspection discipline.
For direct prime or tier-1 aerospace work, AS9100 is usually mandatory. For lower-tier subcomponents, ISO 9001 with aerospace-specific FAI processes is often accepted — but the prime's approved-supplier-list requirements govern.
ITAR posture for defense-adjacent aerospace
Any aerospace work touching defense-controlled technical data (ITAR-covered prints, specifications, or components) requires ITAR-compliant handling: US-person-only access to controlled prints, physical and electronic document control, restricted shipping, no unauthorized foreign disclosure.
Ask any prospective aerospace shop: "How do you handle ITAR-controlled prints?" If they don't know what ITAR means, they can't do defense-adjacent aerospace work. If they say "we don't take ITAR jobs," fine — but confirm your project isn't controlled.
Alloy fluency for aerospace
The aerospace alloy list overlaps with but differs from oilfield: Titanium Grade 5 (Ti-6Al-4V) and Grade 23 ELI are the workhorses. Inconel 718 and 625 for engine components. Waspaloy and A286 for high-temperature. 17-4 PH and 15-5 PH for structural. Aluminum 7075 and 6061 for airframe structural components.
A shop that runs these weekly is set up for aerospace. A shop that specializes in oilfield alloys may or may not have equivalent titanium fluency — worth verifying.
Tolerance and surface-finish expectations
Aerospace often specs tighter tolerances than oilfield: ±0.0002" or ±0.0001" on critical features isn't unusual. Surface finish targets are frequently 16 μin Ra or better on sealing surfaces and structural fillets.
Ask: "What's your routine tolerance on aerospace-grade structural features? What surface finish do you deliver on titanium?" Look for specific numbers backed by CMM and profilometer verification, not marketing language.
First-article inspection depth
Aerospace FAI is deeper than oilfield: AS9102 form-based reporting is standard. Every dimension on the print gets a documented measurement. Every material lot gets certification traceable to the mill test report.
Ask if the shop uses AS9102 forms or an equivalent. If they don't know what AS9102 is, they're not set up for aerospace-grade documentation.
Counterfeit parts prevention
AS9100 explicitly requires counterfeit-parts prevention processes: verified material sourcing, chain-of-custody documentation, tamper-evident packaging where relevant. This matters more for finished components than for raw-material machining, but shops with AS9100 discipline apply the principles across the board.
For high-value structural or engine components, ask specifically about the shop's material-sourcing controls.
Response to AOG (aircraft-on-ground) requests
AOG is the aerospace equivalent of oilfield rig-down: a grounded aircraft costs an operator thousands per hour. Ask any shop expecting your aerospace business: "What's your AOG response capability?"
Realistic answer: same-day or next-day for stocked-material repairs by a shop that already knows the customer. Aspirational answer for first-time customers on unusual alloys: 3–7 days. Honest shops say so.
Frequently asked questions
Is AS9100 required for all aerospace CNC work?
For prime-of-record and tier-1 direct suppliers, usually yes. For tier-2 and lower, primes often accept ISO 9001 with aerospace-specific FAI processes. Check the specific approved-supplier-list requirements.
What's the difference between AS9100 and ISO 9001?
AS9100 is ISO 9001 plus aerospace additions: risk management, product safety, counterfeit-parts prevention, expanded first-article inspection, and specific supplier-monitoring requirements. Same audit rhythm and structure.
Can an oilfield CNC shop do aerospace work?
Depends on the shop. Discipline and equipment often transfer well. Alloy fluency (titanium, Waspaloy) may need to be verified. AS9100 certification typically requires a separate audit — some shops carry both.
What alloys are unique to aerospace CNC?
Titanium alloys (Grade 5, Grade 23 ELI), Waspaloy, A286, aerospace aluminum grades (7075-T6, 6061-T6), and less commonly, exotic superalloys like Hastelloy or Nimonic for engine hot sections.
What tolerances are typical for aerospace CNC parts?
±0.0005" is routine on many features; ±0.0002" or ±0.0001" on critical structural or engine features. Surface finish frequently 16 μin Ra or better on sealing or mating surfaces.
How do aerospace shops handle ITAR?
US-person-only access to controlled prints (verified via I-9 or citizenship documentation), physical document control (locked areas, tracked access), electronic access controls, restricted shipping, and NDA discipline. Shops with ITAR experience have documented processes.
Does B&R Productions handle aerospace work?
Yes — precision structural parts, engine and airframe components in titanium, Inconel, 17-4 PH, aluminum. ITAR-controlled prints handled under NDA with document control. Contact us to discuss specific project requirements.