Intro
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Lesson 07·QC and inspection
Reading a microsection — white layer, diffusion zone, and what the photo isn't telling you
How to look at a vendor's etched cross-section and microhardness traverse, what a porous compound layer means, and which case-depth definition is on the certificate.
9 min readLesson 7 of 12
A vendor ships nitrided H13 mold inserts with a certificate: one 500× photo of an etched cross-section, a hardness number, and "case depth 0.020 inch." No etchant. No traverse. No standard cited. This lesson is how to read what came back and what to ask for before accepting it.