CNC Processing Service Canberra: What to Check Before You Order

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  Key takeaways
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  What each check tells you about a supplier
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  Tolerance and inspection method
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  Machine envelope and part size
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  Material range and stock reality
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  Certification scope and what it covers
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  MOQ, setup cost, and quoting clarity
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  Lead time, shipping, and what starts the clock
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  Confidentiality and file handling
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  Step by step: qualifying a supplier

Any supplier can type ±0.005 mm on a quote. The useful question is which machine holds it and how they prove it. A 3-axis mill with a worn ball screw will drift on a deep pocket long before the operator notices. A simultaneous 5-axis center cutting a one-setup part avoids the re-fixturing error that stacked tolerances come from, which matters when a bore and a face both carry a tight callout.

Ask what gauge is used on the feature you care about. A micrometer reads an outside diameter to ±0.001 mm in the right hands. A CMM reads position and true position across a datum scheme. A pin gauge reads a hole. If your drawing uses GD&T, the CMM report should mirror your datum structure, not a simplified one.

Then ask what ships with the parts. We inspect 100% before shipment and can supply raw material check notes, in-process readings, and final inspection reports on request. If a supplier cannot say what a report contains, assume the tolerance is nominal, not verified.

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  Fine finishRa 0.2–0.8 μm for sealing faces and bearing bores.
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  High finishRa 0.8–1.6 μm covers most mating surfaces.
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  As machinedRa 1.6–3.2 μm is fine for brackets and covers.

Size drives machine choice more than any other variable. A 4,000 mm long rail cannot be cut on a 500 mm table, and a supplier who quotes it anyway is either farming it out or hoping you will not ask. Our largest travel is 4,000 × 400 × 150 mm. Medium work runs on 750 × 1,150 × 550 mm and 600 × 600 × 600 mm envelopes, and compact work on 500 × 500 × 450 mm and 500 × 310 × 200 mm.

Rotary work is a separate question. A Ø400 mm rotary table supports 4-axis indexing and continuous 5-axis contouring. If your part has features on five faces, or a compound angle that would need three setups on a 3-axis machine, ask whether it can be cut in one setup. Each extra setup adds a datum shift and a chance for chips to sit under a clamp.

For thin-wall parts, the envelope is not the limit. Deflection is. A 1.5 mm wall in aluminium at 4,000 mm length will chatter unless the supplier roughs, stress-relieves, and finishes in separate passes. Ask how they handle it before you approve the process.

A material list is easy to publish. Stock is harder. The useful question is which grades sit on the shelf and which are ordered per job, because ordered stock adds days to the front end of your lead time. For aluminium we run 6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075, and ADC12. Stainless covers 303, 304, 316, 316L, 420, 430, 431, 440C, and 17-4PH (SUS630).

Steel grades include 1018, 1045, 4130, 4140, 4340, A36, and tool steel. Copper and brass run across C101, C103, C110, beryllium copper, C27400, C28000, and C36000. Titanium and special alloys cover TA1, TA2, TC4 (Ti-6Al-4V), Inconel, and magnesium AZ31B / AZ91D. Plastics include ABS, PC, PMMA, POM, PA, PEEK, PP, HDPE, and carbon fibre.

Titanium and Inconel are where suppliers separate. Both work-harden, both generate heat at the cutting edge, and both punish a light rigid setup. If your part is Inconel with a deep pocket, ask for the toolpath strategy and the coolant pressure, not just the material name on a quote.

Certificates are scope documents. ISO 9001:2015 is a general quality management standard and applies to almost any machine shop. IATF 16949:2016 adds automotive-specific requirements around traceability and change control. ISO 13485:2016 adds medical device process controls. ISO 27001:2022 covers information security, which matters when you send proprietary CAD files to an overseas supplier.

Ask for the certificate number and the expiry date. Ask which site it covers. A group certificate that names a different plant than the one cutting your parts is not evidence about your parts. We hold all four and can send copies with the quote.

For defense and aerospace work in the Canberra region, certification is often only the entry ticket. The next question is whether the supplier has a documented process for first article inspection and whether they will hold a revision of your drawing, not just the latest one.

Minimum order quantity is where small engineering teams get squeezed. Many shops will not open a machine for fewer than 50 parts. We have no minimum order quantity, from one prototype to 10,000+ part runs. That matters for a Canberra team validating a design before tooling spend.

Read the quote structure, not just the total. Unit price, setup, programming, finishing, and freight should each appear as a line. If finishing is folded into the unit price, you cannot compare two suppliers fairly, because one may be quoting anodizing and the other a bare machined surface.

Ask how revisions are handled. A drawing change after programming starts should trigger a written delta, not a new lump sum. Ask too whether the quote includes first article inspection or charges for it separately.

Lead time means different things to different suppliers. Some count from purchase order, some from drawing approval, some from receipt of material. Pin that down before you compare numbers. Our sequence is quotation and free DFM analysis within 12 hours, production starting within 24 hours, and parts shipping in 3–5 days.

Canberra adds a freight layer that a Southeast Asian or Chinese supplier has to plan for. Parts travel by air or sea, clear customs, and then move inland. Ask whether the quoted lead time ends at the factory gate or at your dock, and who handles the customs paperwork.

Historical late-delivery probability across our orders sits below 2%. That is a history, not a guarantee, and we do not promise a delivery date on a page. What we can do is give you a start date and a ship date in writing, and flag risk early when a material is short.

Canberra work often includes defense-adjacent, medical, and research hardware where the drawing itself is sensitive. Ask how uploads are stored, who can open them, and how long they are retained. We treat uploads as secure and confidential and can sign an NDA on request.

ISO 27001:2022 is the standard that covers this systematically: access control, incident handling, and supplier security. If a supplier cannot describe their file access policy in plain terms, that is a signal about how they handle everything else.

Also ask who owns the CAM program and the fixture design. If you switch suppliers later, you want the setup knowledge to be reproducible, not locked in one person's head.