Swiss CNC Manufacturer Guide

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  What matters before you send an RFQ
• 2
  Which shop fits your part
• 3
  Check 1: tolerance claims and how they are measured
• 4
  Check 2: lead time from quote to shipped parts
• 5
  Check 3: certifications and the risk each one covers
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  Check 4: MOQ, quotingscope and what the price includes
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  Check 5: what a machine list does not tell you
• 8
  How to qualify a supplier in 6 steps

Every shop will say it holds tight tolerance. The useful question is how the number was measured. A ±0.005 mm claim on a 4,000 mm part is a different job than the same claim on a 20 mm stainless pin. Ask which machine runs the feature, how the part is held, and what inspection step confirms it.

On our floor, that number comes from 16 simultaneous 5-axis machining centers, 12 four-axis mills and 27 three-axis machines, plus 16 mill-turn centers. The part geometry decides the machine. A long shaft with cross-holes belongs on a mill-turn center, not on a three-axis mill with three re-fixturings.

Surface finish follows the same logic. Ra 0.2–0.8 μm is a fine finish that usually needs a separate operation. Ra 0.8–1.6 μm is a normal high-quality machined surface. Ra 1.6–3.2 μm is as-machined and often fine for brackets or covers. If a quote lists one finish for every face, the quote is not finished yet.

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  Ask for the measurement methodCMM, optical or hand tools give different confidence levels.
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  Match finish to functionSealing faces need Ra 0.8 μm or better; clearance holes rarely do.
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  Check the datum planA tolerance without a datum reference is not a specification.

Lead time is not one number. It breaks into quoting, DFM feedback, material purchase, machining and inspection. A shop that quotes in a week will usually start production in a week. Ask for each stage separately and the answer becomes useful.

Our published figures are: quotation and free DFM analysis within 12 hours, production can start within 24 hours, and parts ship in 3–5 days. Historical late-delivery probability is below 2%. Those numbers assume the drawing is complete and the material is standard.

Material is the usual hidden delay. 6061, 303 and 304 stainless are normally in stock. Inconel, titanium TC4 and beryllium copper often are not. If your part uses one of those, say so in the RFQ and expect the material stage to dominate.

Oversize parts add another layer. A 4,000 mm workpiece needs the right travel and a fixture plan before anyone cuts metal. Confirm both before you commit to a date.

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  Split the timelineQuote, DFM, material, machining, inspection.
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  Flag exotic material earlyInconel and titanium drive the schedule.

Certificates are easy to list and easy to misread. Each one covers a different risk. ISO 9001:2015 covers the quality management system. IATF 16949:2016 covers automotive production and the traceability that goes with it. ISO 13485:2016 covers medical device manufacturing. ISO 27001:2022 covers information security.

If your part goes into a car, IATF matters. If it goes into a surgical instrument, ISO 13485 matters. If your drawings are the valuable part of the job, ISO 27001 matters because it governs how files are stored and who can open them.

Ask to see the current certificate and the scope. A valid certificate for the wrong scope does not help you. This check takes ten minutes and prevents most supplier surprises later.

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  ISO 9001:2015Baseline quality system for general machining.
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  IATF 16949:2016Automotive programs and traceability.
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  ISO 13485:2016Medical devices and process validation.
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  ISO 27001:2022Design file confidentiality and access control.

A minimum order quantity tells you which customers the shop is built for. A shop with no MOQ can run one prototype and then 10,000+ parts without changing how it quotes. That flexibility matters when a design is still moving.

Ask what the unit price includes. Machining, material, finish, inspection and packaging are often listed separately. A low unit price with finishing and inspection added later is not a low price.

Quotingscope also matters across quantity breaks. Ask for a 1-piece price and a 100-piece price from the same supplier. The ratio tells you how much of the cost is setup and how much is cycle time. If the ratio barely moves, the shop is pricing cycle time into every part.

For prototypes, a free DFM pass is worth more than a small discount. It catches thin walls, deep pockets and tolerances that cannot be reached before the machine starts.

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  No MOQOne prototype to 10,000+ part runs.
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  Ask for two quantity breaksThe ratio reveals setup versus cycle time.
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  Confirm what finishing costsAnodizing and plating are separate operations.

A machine list is a starting point, not a capability. Two shops can own the same 5-axis model and deliver very different parts. The difference is the fixture, the tool path and the person who wrote it.

Look at the support functions around the spindle. Material stock, in-house finishing, inspection equipment and a sample room all shorten the path from drawing to part. We keep a sample center where you can review prior work before committing to a program.

We run 127 high-precision CNC machines across 3 wholly-owned plants covering 7,600 m², with 150 technicians. That scale is useful for overflow and for keeping a program moving when one plant is loaded.

The last check is communication. A supplier who answers a technical question with a specific number is easier to work with than one who answers with an adjective.

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  In-house finishingAnodizing, plating, powder coating, black oxide.
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  Sample reviewInspect similar parts before production.
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  Technical answersNumbers, not adjectives.