nc1-viewer.com
nc1-viewer.com
NC1-Viewer.com is a free, browser-based viewer and editor for DSTV .nc1 files — the plain-text CNC format that moves structural steel part data between detailing software (Tekla Structures, Autodesk Advance Steel, and others) and shop-floor machinery such as beam drill lines, saws, and plasma or laser cutters.
NC1 files are exchanged constantly in steel fabrication, but actually looking at one has traditionally required installing a desktop viewer, or opening the raw text and mentally reconstructing the geometry from coordinate lists. That is slow when a detailer just wants to sanity-check an export, a shop needs to verify a customer's files before cutting material, or an estimator wants to see what a part looks like.
NC1-Viewer.com removes that friction: open the site, drop in your .nc1 files, and see each part rendered as dimensioned 2D face views and an interactive 3D model — holes, slots, copes, cuts, contours, and markings included. It runs on any modern browser with nothing to install.
Structural steel data is often commercially sensitive, so the viewer is built around a simple rule: your files are parsed and rendered entirely in your browser. For normal viewing, no file data is uploaded to our servers, harvested for analytics, or used for ad targeting. The details are in our Privacy Policy.
Viewing is free and requires no account. A Pro subscription funds the project and adds professional workflow features such as editing hole positions and header fields and exporting corrected NC1 files. The free tier is additionally supported by advertising.
The parser implements the DSTV standard interface for structural steel pieces — the ST header block plus BO (holes), AK/IK (external and internal contours), SI (numbering), PU/KO (markings), KA (bends), and related blocks — including real-world quirks like slotted holes, counterbores, and plane-suffixed block variants that different CAD exporters produce. Rendering uses hardware-accelerated 2D and 3D graphics in the browser. The parser is exercised against an extensive automated test suite and a library of sample files from different exporters. If you find a file that renders incorrectly, we genuinely want to hear about it — see the Contact page.
We also publish free reference material on the DSTV format itself, based on the format specification and our experience implementing it:
Questions, bug reports, feature requests, or a file that will not parse? Email contact@nc1-viewer.com or use the Contact page.