Vendor handoff: what goes on the print to the heat treater, nitride house, and polisher

Every line on the print drives vendor scope. Vendors plan against the most restrictive interpretation of each call. Three categories of over-specification quietly add scope to forge die vendor work without buying any die life.

Traceability to acceptance levels the part does not need. NADCA #207 Premium Acceptance Class A includes inclusion ratings, banding limits, and ultrasonic inspection that matter for high-volume aerospace die casting and rarely matter for a small-run forge die. Calling Class A when Class B or no acceptance class will do adds substrate scope without changing service life. The same applies to AMS quality levels on heat treat: if the part does not actually need the documentation chain that AMS 2759/3 mandates, citing the standard for the cycle parameters alone is acceptable without invoking the full certification package.

Nadcap accreditation on the heat treater or the nitride house when the application does not require it. Nadcap is the aerospace audit standard. It buys process discipline and documentation traceability that aerospace forging programs need and that commercial forge dies almost never do. A Nadcap heat treat or nitride job carries documentation overhead beyond what a non-Nadcap cycle requires. If the part is not going into an aerospace program, calling Nadcap on the print buys overhead, not capability.

Tolerances tighter than the application uses. A 0.02 mm flatness call on a forge die that runs against a 0.1 mm bolster gap is the print writer's reflex, not a requirement. A Kn trace called out on a nitride job that does not require closed-loop control is the print writer covering themselves at the vendor's expense. Polish to Ra 0.1 µm on cavity surfaces that wear at 0.4 µm is shop pride, not engineering. Each over-call is invisible on the certificate and visible in the vendor's schedule.