Guides / Industries

Swiss Machining for Aerospace Fasteners and Small Components

September 21, 2026

Aerospace work on Swiss-type lathes covers a narrower band of parts than medical or connector work, but the parts are valuable and the programs are long. Small fasteners, pins, bushings, fittings, sensor components, actuator parts and hydraulic components all sit in the size range where a sliding headstock lathe is the right machine.

The machining is often the straightforward part. The documentation, the approvals and the process control around it are where an aerospace order differs, and where an unprepared buyer loses months.

The parts

Typical Swiss aerospace work:

• Threaded fasteners, studs and bolts in the small diameter range
• Pins, clevis pins and shear pins
• Bushings and spacers
• Hydraulic and pneumatic fitting components
• Sensor bodies and probe components
• Actuator internals such as spools and pistons
• Electrical contact and connector components for airframe harnesses

Materials skew toward stainless, titanium, high strength alloy steels, nickel alloys such as Inconel and occasionally aluminum. Several of these are difficult to machine, which pushes cycle times up and tool life down compared with industrial equivalents.

Material certification is not optional

On aerospace parts, material control starts before the bar arrives.

Expect to specify:

• The material specification, such as an AMS specification, rather than a generic grade name
• The condition, including heat treatment state at delivery of the bar
• Mill certification, with heat or lot numbers traceable to the finished part
• Approved source requirements, if your customer maintains an approved raw material source list
• Country of melt or origin, where your contract requires it

That last point catches people out. Some aerospace contracts carry requirements about where the material was melted, and a shop that buys bar on price without checking can deliver perfectly good parts you cannot use. Raise it at RFQ stage.

Lot traceability then has to hold through machining, every outside process and packaging. Agree what a lot is and whether lots may be combined at any step.

Quality system and approvals

AS9100 is the aerospace quality management standard, built on ISO 9001 with additional requirements around configuration management, risk, counterfeit part prevention and first article inspection.

Whether you need it depends on your customer and your own quality system, not on the word aerospace. Flight critical hardware usually requires it. Ground equipment and non critical components often do not.

Whatever the requirement, verify rather than assume:

• Ask for the certificate, check its scope and its expiry
• Check the scope covers the site doing your work and the processes involved
• Ask whether the shop appears on any customer approved supplier list relevant to your program
• For special processes, ask which approvals the outside processors hold

Treat any claim about approvals as something to confirm through the issuing body or your customer’s own list. This is routine and no serious supplier objects.

Special processes

Most of the processes that follow machining on an aerospace part are classed as special processes, meaning the result cannot be fully verified by inspecting the finished part.

The common ones:

• Heat treatment
• Plating, including cadmium replacements, nickel and chrome
• Anodizing and chemical conversion coating
• Passivation
• Shot peening
• Penetrant and magnetic particle inspection
• Dry film lubricant

Each one normally goes to a specialist processor holding specific approvals. What you need to establish is who those processors are, what approvals they hold, whether your customer accepts them and how their certificates reach you with the parts.

Plan lead time accordingly. Each outside process adds transit both ways plus the processor’s own queue, and an approved processor is not always a fast one. The lead time guide covers how these stack.

First article inspection

Aerospace first article inspection usually follows AS9102. It is more prescriptive than a general first article report and it takes longer to produce and to review.

Expect:

• A ballooned drawing covering every characteristic
• Forms recording part identification, raw material and special process details
• Results recorded against each characteristic with the measurement method
• A requirement to repeat the first article when specific things change, such as material source, process, tooling or a production gap

That last point matters for planning. If a part sits dormant for a defined period, a new first article may be required before the next order, which is a schedule item and a cost item. Ask the shop what triggers a re-submission.

For the general principles behind inspection and gauge capability, the inspection guide applies here too.

Configuration and change control

Aerospace programs run for years. Parts made in year six must match parts made in year one.

Agree up front:

• The shop may not change material source, outside processor, tooling approach or process without notifying you
• Drawing revisions are controlled, and the shop confirms which revision it is building
• Obsolete revisions are removed from the floor
• Records are retained for the period your contract requires, which is often long

A shop accustomed to aerospace will have all of this documented already. A shop that treats it as unusual is telling you something useful.

Export control

Some aerospace parts, drawings and technical data are subject to export control regulations, which restrict who may receive technical data and where work may be performed. Whether your part is affected depends on its end use and classification.

This is a determination for your compliance or legal function rather than for a supplier or a sourcing platform. If your part may be controlled, establish the classification before you release drawings to anyone, and share technical data only in ways your compliance function has approved. Our RFQ form lets you request an NDA before files are released, but an NDA is not an export control determination and should not be treated as one.

Counterfeit prevention and provenance

Counterfeit and fraudulently represented parts and material are a specific concern in aerospace supply chains, and AS9100 addresses them directly.

For a machined part the risk sits mostly in the raw material. Bar bought on price through a broker with an unverifiable certificate is the classic exposure. The part machines fine, measures fine and may not be the alloy the certificate claims.

What a buyer can reasonably ask:

• Where the shop buys bar, and whether it buys from mills or authorized distributors rather than brokers
• Whether certificates are verified against the mill rather than accepted as received
• How material is identified and segregated in stock, so that lots cannot be confused
• What happens to material whose certification is incomplete
• Whether the shop can supply the full certificate chain with the parts

These are ordinary questions in aerospace and a shop working in the sector will answer them without hesitation.

Program length and obsolescence

Aerospace programs outlast most things. A part first made this year may still be ordered in fifteen years, and that has sourcing consequences worth thinking about at the start.

Tooling. If special tooling was made, establish who owns it and where it is stored.

Records. Confirm the retention period covers your contractual obligation, and ask what happens to records if the shop is sold or closes.

Material availability. Some alloys and some bar sizes become harder to source over time. If your part uses an unusual size, that is a risk to note.

Re-qualification triggers. A production gap, a material source change or a process change may require a new first article. Knowing the triggers lets you plan around them rather than discover them.

Second source. For a part that matters, a qualified second source is insurance. It costs a second first article and it removes a single point of failure. Deciding this early is cheaper than deciding it during a shortage.

Cost expectations

Aerospace parts cost more than their geometry suggests, and the reasons are mostly outside the machine:

• Difficult materials with slower cycles and shorter tool life
• Certified raw material at a premium, sometimes from a restricted source list
• Documentation effort per lot
• First article preparation and any re-submission
• Multiple approved outside processes, each with its own minimum charge
• Lower volumes than commercial work, so setup is spread over fewer parts

Reducing cost here rarely comes from negotiating the machine rate. It comes from realistic tolerances, standard features, consolidated orders and not requiring documentation you do not need. The design guide covers the geometry side.

What to send

1. STEP file and drawing at a controlled revision
2. Material specification and any source restrictions
3. Special processes with their specifications
4. Quality system and first article requirements
5. Documentation and record retention requirements
6. Whether the part is export controlled, and your handling instructions
7. Order quantity and expected program volume

The proofs your industry adds are summarized in Swiss machining supplier qualification.

Getting aerospace parts quoted

Send the package through the RFQ form. We match your part with up to three shops that run Swiss-type lathes, and you can request an NDA before files are released. Replies come within 24 business hours.

We are a matching service rather than a machine shop, so approvals, certificates and first article reports come from the shop that makes your part. Verify them directly with that shop and with your customer’s approved supplier list.

Frequently asked questions

Keep reading

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