Most lots pass standard visual checks. Some deserve more attention before they reach a production line.
Paperwork that does not match
Inconsistent date codes, lot numbers or labels between packaging and parts are a reason to look closer.
Marking and surface anomalies
Uneven marking, sanding marks or blacktopping can indicate remarked parts.
Lead and terminal condition
Signs of previous soldering, oxidation or re-tinning suggest refurbished stock.
Unusual sources or pricing
Parts offered far below market from an unfamiliar source call for X-ray and electrical testing.
High-consequence applications
For safety-critical builds, a deeper test plan is justified whatever the visual result.