Qualifying a contract machining supplier in Turkey means proving, before the first order, that the company is a registered manufacturer, that its certificates are valid and cover the site and process, and that its measuring system can show your parts meet the drawing. Work through five stages (screening, document review, audit, pilot order, monitoring) and decide at each gate on evidence, not on what the supplier tells you.
What does it mean to qualify a contract machining supplier?
Qualification produces a file that justifies releasing series orders. The five stages are:
- Screening: Confirm the legal entity, the address of the machining site and the certificates named in the quote. Stop here if the supplier cannot say which site makes your part.
- Document review: Collect certificates, registry documents, a calibration list, a sample inspection report and a sample material certificate.
- Audit: Visit the site or run a remote audit. ISO 19011:2026 gives guidance on running an audit programme and conducting audits; EN ISO 19011:2018 was withdrawn on 15 June 2026. Automotive customers use the VDA 6.3:2023 process audit, which includes purchasing requirements and notes on remote audits.
- Pilot order: Make a small lot against the real drawing and check it yourself.
- Monitoring: Track delivery, nonconformances and corrective actions, and requalify when something changes.
Which checks belong on a supplier audit checklist?
Each of the eight checks below has a document you can ask for and a finding that should stop the process until it is explained.
Table 1. Supplier audit checklist for a contract machining supplier
| # | Check | Evidence document | Red flag |
|---|---|---|---|
| 1 | Legal entity and production site | Trade registry extract, tax certificate, industry registry certificate for the site | The contracting company is not the one that machines; the address differs between documents |
| 2 | Quality certificate | ISO 9001 certificate with scope, site and expiry date, from an accredited body | Issuer not accredited; scope omits machining; site missing; certificate expired |
| 3 | Equipment and capacity | Machine list with travel ranges, maintenance records | No machine in the list fits the part envelope; no maintenance records |
| 4 | Measurement system | Calibration certificates, instrument list, sample inspection report | Calibration overdue; no instrument for the critical features |
| 5 | Material traceability | EN 10204 3.1 certificate with batch or heat number, incoming inspection record | A generic mill sheet without batch number; no way to link certificate to part |
| 6 | Subcontracted processes | List of subcontractors for heat treatment, plating, anodising, with their certificates | Subcontracting that was not declared or approved |
| 7 | Drawing and revision control | Controlled drawing register, revision on the work order | Operators work from printouts of unknown revision |
| 8 | Nonconformance handling | A past corrective action report, a quarantine area for rejected parts | No record of any past nonconformance, or no containment of rejected parts |
Source: Ertaş Engineering, compiled from the standards and registers listed under Sources.
How do you verify an ISO 9001 or IATF 16949 certificate?
A certificate is worth what its issuer and its scope are worth. Check who issued it, what it covers and whether it is still valid, in that order.
The issuer should be a certification body accredited for management system certification by a national accreditation body that signs the EA multilateral agreement (MLA). TÜRKAK, the Turkish accreditation body, appears in the EA directory as an MLA signatory with management system certification, calibration and testing among its scopes (last peer evaluation March 2024, next re-evaluation March 2028). The directory links each scope to the national body's database of accredited organisations. A certification body from another country works as well, as long as its own accreditation body is listed the same way.
Then read the scope. It should name the legal entity, the site address, the standard with its edition, and an activity that includes machining. Ask the certification body to confirm validity in its register rather than relying on a PDF.
Table 2. Where to verify each claim
| Claim | Where to verify | What it proves |
|---|---|---|
| ISO 9001 certificate | Certification body's register; the body's entry in the accreditation body's database | The certificate exists and the issuer is accredited |
| IATF 16949 certificate | IATF Certificate Validity Check; IATF-recognised certification body with IATF logo and number | The certificate is recognised by automotive OEMs |
| Calibration certificates | Accreditation status of the laboratory for ISO/IEC 17025 | Measurements trace to a recognised standard |
| Industry registry certificate | Copy of the Sanayi Sicil Belgesi, address matched to the site | The production site is registered with the ministry |
Source: IATF Global Oversight; VDA QMC; EA directory of MLA signatories; Sanayi Sicil Bilgi Sistemi. As of 2026-10-30.
Two edition questions come up in 2026. ISO published ISO 9001:2026 on 16 September 2026. Organisations certified to ISO 9001:2015 have until 30 September 2029 to transition, and from 31 March 2028 new accredited certifications may only be issued to the 2026 edition, so a 2015 certificate today is normal and not a red flag. For IATF 16949, the 2016 edition is current; the IATF started a revision in October 2024 and published a status communiqué on 30 July 2026. VDA QMC states that automotive OEMs and most of the supply chain recognise only IATF 16949 certificates issued by an IATF-recognised certification body. The certificates article covers what each one does and does not say about a shop.
How do you confirm a Turkish supplier is a registered manufacturer?
Ask for two documents. The first is the trade registry extract with the MERSIS number; MERSIS is the central registry system of the Ministry of Trade. The second is the industry registry certificate, the Sanayi Sicil Belgesi. Under the Industry Registry Law (No. 6948), industrial enterprises register with the Ministry of Industry and Technology and must show the certificate to officials on request. The ministry's portal states that each production site is registered separately.
Match the name and address across the trade registry extract, the industry registry certificate, the ISO certificate and the quote. A mismatch can have a harmless cause, such as a head office in one district and the shop in another, but ask for the explanation in writing.
If you buy through a trading company or a network, ask the same question one level down: which site machines the part, and which of the documents above belong to that site. Ertaş Engineering sources from an audited network in Bursa, so this applies to us as well.
How do you audit measurement and material traceability?
Trace one finished part backwards. Pick a part from stock, find its inspection report, identify the instrument that took each reading, open that instrument's calibration certificate, then find the material certificate for the batch. Four links have to connect: part, report, instrument, material. A gap in any one means the supplier cannot prove conformity after the fact.
For material, the document to ask for is the EN 10204 inspection certificate; DIN Media lists EN 10204:2004 (DIN EN 10204:2005-01) as the current edition. A type 3.1 certificate should carry the batch or heat number that is marked on the delivered bar or on the parts. The EN 10204 guide explains when type 3.2 is needed.
For measurement, ask for calibration certificates from laboratories accredited to ISO/IEC 17025; TÜRKAK's MLA scopes include calibration. Ask which features are measured on a CMM and which with hand gauges, and read one inspection report with the drawing next to it. Reports that show the same value on every part, or that skip the dimensions you flagged as critical, are a finding. See inspection reports, CMM and Cpk for how to read capability data.
What should a pilot order prove?
Audits show a supplier's system; a pilot order shows whether the system produces your part. Use the real drawing revision, the specified material and a small lot, and agree the acceptance criteria before the order, not after delivery.
The supplier should return a first article inspection report with every drawing dimension numbered and measured, the material certificate for the batch, and the process route. Measure a sample yourself at incoming inspection and compare it with the supplier's values. Agreement within the measurement uncertainty of both instruments is the result you want. The first article inspection guide describes the report format.
Release series orders only after the pilot lot is accepted in writing, and record the drawing revision, material and process route that were approved.
When does a qualified supplier need requalification?
Treat the qualification as valid for a defined scope and review it when that scope changes. Triggers are an expired or withdrawn certificate, the move to ISO 9001:2026 (due for existing certificates by 30 September 2029), a new production site, a new subcontractor for a special process, a new material or a changed drawing revision on a critical feature, and repeated nonconformances of the same type. Keep the audit file, the pilot report and each corrective action report together, so the next review starts from evidence.
Frequently asked questions
- How do I verify an ISO 9001 certificate from a Turkish supplier?
- Check three things: the certification body is accredited for management system certification, the certificate lists the supplier's legal name and the address of the site that machines your part, and the certification body confirms it is valid in its own register. TÜRKAK, the Turkish accreditation body, is an EA MLA signatory for management system certification.
- Is an ISO 9001:2015 certificate still acceptable?
- Yes, as of 2026-10-30. ISO published ISO 9001:2026 on 16 September 2026, and organisations certified to the 2015 edition have until 30 September 2029 to transition. From 31 March 2028, new accredited certifications may only be issued to the 2026 edition.
- Can I audit a Turkish machining supplier remotely?
- Partly. Documents, records, calibration files and a live walk-through of the shop can be covered remotely, and VDA 6.3:2023 contains notes on remote audits. Machine condition, part handling and storage are easier to judge on site.
- Which documents show that a Turkish company is a manufacturer?
- A trade registry extract with the MERSIS number, and the industry registry certificate (Sanayi Sicil Belgesi) of the Ministry of Industry and Technology for the production site. The address on both should match the address on the quality certificate and the site you audit.
- What should a pilot order prove?
- That the supplier can make the part to your drawing revision from the specified material and document it: a first article inspection report covering every drawing dimension, an EN 10204 material certificate linked to the batch, and measured values that agree with your own incoming inspection.
Sources
- ISO TC 176: ISO 9001:2026 release and transition dates (ISO technical committee site)
- EVS-EN ISO 19011:2026, Guidelines for auditing management systems (Estonian Centre for Standardisation and Accreditation)
- VDA Volume 6 Part 3, Process Audit, edition 2023 (VDA QMC)
- IATF Global Oversight: IATF 16949:2016, revision status and Certificate Validity Check
- IATF certification bodies and recognised certificates (VDA QMC)
- Directory of EA members and MLA signatories, entry TÜRKAK (European co-operation for Accreditation)
- Sanayi Sicil Bilgi Sistemi, industry registry (Ministry of Industry and Technology, Türkiye)
- MERSIS, Central Registry System (Ministry of Trade, Türkiye)
- DIN EN 10204:2005-01, Metallic products, types of inspection documents (DIN Media)
Questions on a drawing? sales@ertas.engineering