The short answer
When parts arrive out of spec, the first job is containment and evidence. The second job is deciding disposition without making the problem worse.
Start with containment
Stop the affected lot, segregate suspect inventory, and document the nonconformance clearly with measured evidence tied to drawing revision. If assemblies or field units may be affected, escalate immediately. Containment is more important than assigning blame in the first hour.
The worst move is letting questionable parts drift deeper into the process.
Get the facts straight
Confirm the measurement method, datum setup, sample size, and actual deviation. Many disputes are really metrology mismatches or drawing-interpretation issues. Others are real escapes. You need to know which one before choosing scrap, rework, use-as-is, or return.
Facts first, emotions later.
Choose disposition carefully
Use-as-is only works if engineering signs off on fit, form, and function. Rework needs a defined route that does not create hidden damage. Return to supplier may be right, but only after the deviation is understood. Scrap is cleanest when function or traceability is compromised.
There is no adult version of 'close enough' without documented authorization.
Prevent recurrence
Ask for root cause, corrective action, and evidence that the process changed. But do not demand an elaborate 8D for every minor one-off issue. The response should match severity and recurrence risk.
Good buyers drive closure, not theater.
What an experienced buyer does next
Related reading: How to write an inspection plan for machined parts and Material certifications demystified: certs of conformance, MTRs, and chemical analysis.
The right move is usually to define the real functional requirement, remove the decorative requirements, and let the supplier build a route around what actually matters.
Comparison table where relevant
| Response step | Purpose | Bad habit |
|---|---|---|
| Containment | Stops spread of suspect parts | Keep building and hope |
| Measurement review | Confirms actual deviation | Argue before checking datum setup |
| Disposition | Protects function and traceability | Use-as-is without approval |
| Corrective action | Reduces recurrence | Demanding paperwork without learning |
How to specify this in your RFQ
Document the nonconformance with measured values, photos if useful, revision level, and quantity affected. Tell the supplier whether you need replacement, rework proposal, or root-cause response first. A precise NCR gets faster resolution than an angry email.
A clean RFQ does not just list requirements. It separates must-haves from preferences so the supplier can optimize where it is safe.
Have a part that needs quoting? Email your drawings to rfq@precisionmachining.co -
we return a competitive quote within 24 hours. Phone: +1 312-579-0808.