Frequently Asked Questions

Questions about STEP and STEP-NC International Data Standards

What is STEP?
The Standard for Product Model Data Exchange (STEP) is a data standard created by an international team of more than 500 CAD, CAM and CAE experts. STEP gives an explicit and complete representation of product data throughout its entire life cycle. STEP first became an ISO standard in 1994 and over the last five years all of the leading CAD software vendors have implemented STEP data translation. It is estimated that more than two million CAD stations now contain STEP data translators.

What is STEP-NC?
STEP-NC is an extension of STEP that defines a machine independent bi-directional data standard for Computerized Numerical Control (CNC) systems. Using STEP-NC, an external system such as a CAM or CAD/CAM system can create machine independent CNC control instructions for making a part. Any CNC machine tool that has the necessary resources should be able to process the STEP-NC data.

What is the relationship between STEP and STEP-NC?
STEP defines a standard for CAD design data. STEP-NC is an extension of STEP that enhances this design information with manufacturing information. It includes information about the stock, its manufacturing features, inspection quality tolerances, the tool requirements, manufacturing process sequence, speeds, feeds, and many other process parameters.

Why is STEP-NC important to Manufacturers?
The rich 3D modeling information in STEP-NC makes CNC systems easier to program and safer to use. The project that developed STEP-NC has estimated that it can reduce the time required to program a CNC by about 35%, reduce the number of drawings that have to be sent from design to manufacturing by about 75% and decrease the time required to machine parts on CNC tools by about 50% for small to mid-sized job lots.

How Does STEP-NC Work?
STEP-NC replaces the RS274D M and G code standard as the primary interface between CAM and CNC systems. With STEP-NC, a CNC system is given a full description of the part and the manufacturing process. This description allows the CNC to perform complete safety checking before it begins to make the part, and it allows the CNC to optimize the manufacturing process for its current operating conditions.