STEP-NC (ISO 10303 AP238)
STEP-NC, formally ISO 10303 AP238, is a standard that extends the STEP product data model to machining. Instead of the 1950s-era G-code emitted by a post-processor, STEP-NC carries associative, machine-portable manufacturing programs that reference the part geometry, features, tolerances and operations directly, so the same program can in principle run on any compliant controller without a machine-specific post-processor.
Why it matters
STEP-NC spent more than fifteen years trying to eliminate post-processors. Boeing and NIST validated portable five-axis programs, yet vendor adoption two decades on is close to none. The reason is structural: the post-processor and the controller dialect are moats, and nobody who owns that layer profits from neutralizing it. The unmanaged G-code file is an equilibrium, not an oversight, and that equilibrium is the main obstacle to closing an Adaptive Manufacturing loop.
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Cite this definition
Finocchiaro, Michael. “STEP-NC (ISO 10303 AP238).” DemystifyingPLM PLM Glossary, 2026, https://www.demystifyingplm.com/glossary/step-nc-iso-10303-ap238