The questions that separate a good shop from a wrong fit
A directory description cannot establish fit for a particular part. Compare the drawing and contract requirements with the supplier's current written response, then have the responsible technical and quality owners review any open point.
1. Capability — can they actually make your part?
Ask the supplier to confirm the proposed process, accepted material designation and condition, maximum part and stock envelope, workholding assumptions, quantity and any subcontracted operation. See milling vs turning and the 5-axis research guide, but let the responsible supplier propose its manufacturing route.
2. Tolerances and inspection
Ask the supplier to review every critical characteristic and state the measurement method and record it will provide. Do not assume a machine, instrument or inspection report is available. Define acceptance and retention requirements in the drawing or contract.
3. Quality systems and certification
There is no universal certificate requirement for every CNC purchase. Derive quality-system and conformity requirements from the customer, drawing, contract and applicable law. For any claimed certificate, verify the legal holder, standard and edition, certified site, scope, certification body and current validity. ISO describes ISO 9001 as a quality-management-system standard and ISO 13485:2016 as specific to medical-device quality-management requirements; neither page certifies a supplier.
4. Capacity and lead time
Ask for written quote validity, earliest start assumption, manufacturing duration, subcontract steps, inspection and finishing time, dispatch basis and what restarts the schedule. Capacity and lead time can change; re-confirm them when ordering and after any revision.
5. Communication and DfM input
Record questions, assumptions and proposed design changes. A supplier suggestion is not approved until the responsible designer accepts it and the controlled revision is updated. Agree who may communicate technical changes and where approvals are stored.
6. Pricing transparency
Ask what is included and excluded: setup, programming, material, tooling, first-off work, inspection, reports, finishing, packaging, delivery, taxes and later reorder assumptions. The quote-factor guide provides a comparison table without asserting a market price.
7. Data, drawings and IP handling
CNC quotes often involve drawings, STEP files, prototype details or commercially sensitive geometry. Ask how files are handled, whether an NDA is possible, who sees the drawing, and whether the shop will delete or retain files after quoting. Do not send regulated, medical, personal or confidential customer data unless your own handling route is approved.
Red flags
No physical address or named people. Unwilling to discuss materials or tolerances. A single suspiciously round price with no breakdown. No reviews, portfolio or references. Pressure to commit before a drawing review. Claims of certification or capacity that are not backed by current evidence. Reselling your enquiry as a lead without telling you.
A quick scorecard
| Check | Good sign |
|---|---|
| Capability | Has made similar parts; right process, axes, material, size |
| Inspection | Written method and record for each required characteristic |
| Quality evidence | Contract-derived requirement; holder, scope, site and validity checked |
| Schedule | Written assumptions, validity and revision effect |
| Communication | Named technical contact and controlled change route |
| Quote | Inclusions, exclusions, taxes and delivery basis stated |
| Files and IP | Clear answer on drawing access, NDA and file retention |
The shortcut
Comparing shops one by one is slow, but skipping the comparison is risky. Start with the Irish supplier directory, use the cost guide to understand quote structure, then use the quote request path to prepare a concise brief. No directory or form can guarantee supplier acceptance or response.
Frequently asked questions
How do I choose a CNC machining shop in Ireland?
Compare current written evidence for the process, material, part envelope, inspection, quality requirements, schedule, quote scope and file handling required by the exact drawing revision.
What certifications should a CNC shop have?
There is no universal list. Derive requirements from the drawing, contract, customer and applicable regulation, then verify certificate holder, standard edition, scope, site, issuer and validity.
What are the warning signs of a bad CNC supplier?
Pause when identity, address, data handling, process, inspection, quality evidence, quote scope or change control cannot be confirmed in writing, or when payment is pressed before the drawing and terms are reviewed.
Should I get more than one CNC quote?
Like-for-like written quotes can expose different assumptions. Compare the same revision, quantity, material, inspection, finish, delivery and tax basis; the lowest total does not by itself establish technical fit.
Get competing quotes from Irish shops
Tell us about your part clearly: material, quantity, tolerances, deadline, finish, inspection and drawings. A precise brief is more likely to get a useful response than a vague "can you make this?" email. Prepare a quote request →