This is what a buyer checks before they shortlist a metals and metalworking supplier.
How do I find a CNC machine shop whose website proves tolerance, capacity, and lead time?
A CNC machine shop worth sending a drawing to publishes the processes it runs, the tolerance band it holds under a named standard, and a machine list with makes, travel and counts. ISO 9001 is the baseline quality certificate. Lead time and capacity together tell a buyer whether their part fits the schedule, which is usually the deciding question.
A buyer with a precision part drawing is comparing three shop websites and discarding the ones that do not state a tolerance.
Reviewed 4 August 2026 · Written for CNC machine shopss selling to business buyers
How do I find a CNC machine shop whose website proves tolerance, capacity, and lead time?
What buyers check in metals and metalworking
Three things, in order: what the product is, what the paperwork proves, and when each document gets asked for.
Quality system, with certificate number and…
ISO 9001 or sector quality certificate
Asked at: vendor approval
Full dimensional verification of the first…
First Article Inspection report
Asked at: first production run
Measured dimensions and their tolerance con…
Dimensional inspection report (CMM)
Asked at: acceptance and incoming inspection
First, what the product is
The fields a buyer scans before deciding whether you are worth contacting. Missing one of them usually ends the visit without an email.
- 1
Machining processes
3-axis milling, 5-axis milling, turning, mill-turn and grinding are different capabilities and different shops.
- 2
Tolerance band held under a named standard
Plus or minus a figure in microns or thousandths is the single most important number a CNC shop can state.
- 3
Material groups worked
Aluminium, steel, stainless, titanium and engineering plastics require different tooling and expertise.
- 4
Machine list with makes, travels and counts
Tells a buyer immediately whether their part envelope and volume fit, and signals shop discipline.
- 5
Quality system and certificate
ISO 9001 is the baseline expectation; AS9100 or IATF 16949 indicate sector experience.
- 6
Maximum part envelope per process
A hard filter on the enquiry, and the cheapest one to publish.
- 7
Lead time bands for prototype and production
The number a buyer plans against, and a common tie-breaker between capable shops.
Then the paperwork
Naming the documents you can issue is what separates a supplier who can be audited from one who cannot.
| Document | What it proves | Where it belongs |
|---|---|---|
| ISO 9001 or sector quality certificateAsked at: vendor approval | Quality system, with certificate number and certification body | Publish it |
| First Article Inspection reportAsked at: first production run | Full dimensional verification of the first part against the drawing | Per shipment |
| Dimensional inspection report (CMM)Asked at: acceptance and incoming inspection | Measured dimensions and their tolerance conformance under a coordinate measuring machine | Per shipment |
| Material certificate to EN 10204Asked at: with delivery, often a purchase order condition | Chemistry and mechanical properties of the bar, plate or billet the part was cut from | Per shipment |
| RoHS and REACH declarationAsked at: by eu and electronics customers | Substance compliance for parts destined for the EU or for electronics buyers | Publish it |
| Sample inspection reportAsked at: new supplier evaluation | What your dimensional paperwork actually looks like before the first order | Publish it |
| GD&T capability statementAsked at: technical evaluation | That drawings with geometric dimensioning and tolerancing callouts can be read and held | Name it, share on request |
The shortlist moment
A buyer lines up a few suppliers and keeps the ones whose proof is easy to check. The rest get a closed tab, not an email.
The buyer asks: How do I find a CNC machine shop whose website proves tolerance, capacity, and lead time?
A few suppliers get compared side by side:
A supplier with ISO 9001 or sector quality certificate on the page
Quality system, with certificate number and certification body
A supplier with RoHS and REACH declaration on the page
Substance compliance for parts destined for the EU or for electronics buyers
A supplier with Sample inspection report on the page
What your dimensional paperwork actually looks like before the first order
Is one of them you?
What Plact does for metals and metalworking suppliers
Four jobs, done on your site. Each one is a document buyers in this industry already ask for.
Put the ISO 9001 or sector quality certificate on the page buyers check
Quality system, with certificate number and certification body
Put the RoHS and REACH declaration on the page buyers check
Substance compliance for parts destined for the EU or for electronics buyers
Put the Sample inspection report on the page buyers check
What your dimensional paperwork actually looks like before the first order
Name the GD&T capability statement and share it on request
That drawings with geometric dimensioning and tolerancing callouts can be read and held
What a useful enquiry looks like
A form that collects these fields can be answered properly the first time. A form that collects a name and a message cannot.
Enquiry form · cnc machine shops
Enough to reply usefully, short enough that a buyer finishes it.
- Drawing or model with GD&T callouts
- The single most useful thing on the form, and the basis of any real quote.
- Material grade and condition
- Determines tooling, cycle time and whether the shop runs it regularly.
- Quantity and call-off pattern
- One-off, batch and scheduled volumes price very differently.
- Tolerance and inspection requirement
- CMM reports and FAI add cost and planning.
- Finish and secondary operations
- Anodising, plating, heat treatment and assembly change the quote substantially.
- Required date
- Shops slot work by capacity; a date decides whether the job fits.
An enquiry from this search asks for
- Drawing or model with GD&T callouts
- Quantity and call-off pattern
- Required date
- Material grade and condition
Questions suppliers ask
Should a CNC shop publish its tolerance band publicly?
Yes, with the measurement basis — typically the CMM used and the standard followed. Every shop claims tight tolerances, so the claim alone is worthless; a stated band under a named method is verifiable and is the single thing that separates a precision shop from a generic one in a buyer's eyes.
How much of the machine list should be public?
Makes, models, number of axes, travels and counts. Buyers match a part envelope to a machine, and a buyer who cannot do that on your site will do it on a competitor's. The list also signals discipline: a shop that knows its own fleet is one that plans capacity rather than improvising.
Is publishing prototype lead time bands risky for a busy shop?
No — a band with its basis (queue position, complexity, material) is more useful than a fixed number, and it filters out enquiries whose timeline you cannot meet. A shop that hides lead time loses the buyers who plan around it, and those are usually the better customers.
Documents and standards named here are the ones buyers in this industry commonly ask for; requirements vary by market, customer and contract, so treat this as a starting checklist rather than a compliance list. Clearer pages can help discovery and evaluation. They do not guarantee rankings, AI citations, enquiries or revenue.
Related buyer questions
- Steel and TMTWhat does a buyer check before placing a steel order with a new supplier?
- Industrial componentsWhat does a buyer check before sending you a drawing or an RFQ?
- Steel tube and pipeWhat does a buyer check before ordering tube or pipe?
- AluminiumWhat does a buyer check before ordering aluminium sections or sheet?
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