Identify a plausible source boundary

Compare where particles were found with any opening, drain or known recent maintenance. A pile beneath a work area can have a different explanation from recurring particles emerging at one equipment boundary. Preserve the uncertainty if they could have arrived from outside. A magnetic response or visual colour alone does not uniquely identify an alloy, component or damage mechanism, and should not be presented as proof.

Consider morphology and associated condition

Flakes, curls, granular material and corrosion scale raise different source questions. An appropriate specialist may examine representative material and compare it with the documented parts. Fresh rubbing marks or changed operating evidence can support an investigation, but a single coincident symptom does not establish the source. Do not open covers, reach into an opening or operate the machine to generate more debris.

Particles found after nearby drilling or fabrication deserve comparison with that work before internal wear is asserted. If similar particles recur after that external source is absent, the source question changes. The evidence should distinguish those periods rather than pool all debris together.

Define the next discriminating examination

Ask whether the particles are consistent with an identified surface and whether inspection can bound any associated material loss. If internal wear remains plausible, the reviewer should define the required safe scope and operating disposition. Simply sweeping particles away can remove useful evidence without resolving recurrence. No MARSTON wear-particle threshold, internal material or bearing diagnosis is supplied; the evidence must connect the actual material and location to a supported conclusion.