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Step 7 of 8

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Lesson 11·Specification

Writing the spec — what goes on the print

An annotated nitriding callout template a competent vendor can hit and an incompetent one will refuse, with the eight elements that turn a wish into a spec.

7 min readLesson 11 of 12

Step 7 of 8Masking

Threaded holes, dowel locations, bearing journals, and locating surfaces should not be nitrided. Specify the masking method (copper plating, mechanical masking, anti-nitriding paint) or leave the method to the vendor and specify only the exempt zones. Either way, exempt the masked areas from the case-depth and compound-layer requirements explicitly, or the vendor's certificate will fail at the threads.

Mask threaded holes per drawing zone A4 using copper plating or equivalent. Masked areas exempt from case depth and compound layer requirements.

Quick check

A print marks threaded holes for masking but does not exempt them from the case-depth spec. The vendor masks correctly with copper plating, then sees the threads measure 0 µm case depth on the certificate. Who owns the failure?