Intro
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Nitriding, deeper: why this course exists
The four levers that make one nitriding job different from another, and what a complete nitriding certificate documents that an incomplete one leaves out.
A stamping shop sends H13 die inserts out for nitriding. Two certificates come back. Certificate A says "case depth 0.015 inch, surface 60 HRC" and nothing else. Certificate B includes a microhardness traverse with a measurement standard, compound layer thickness in microns, nitriding-potential setpoints by cycle stage, and a witness coupon identifier. Same word on both POs, same drawing. The two certificates describe different cases.
"Nitriding" is not a single process. It is a family of processes, and within each family member there are at least three controllable variables that change every measurable outcome: case depth, surface hardness, compound-layer thickness and phase, distortion, corrosion resistance, and the bulk hardness left in the core. If the print does not constrain those variables, the vendor picks them. The difference shows up in tool life six months later.