Direct Answer
A DSTV (NC1) file contains coded records for: the member profile (section type and size), overall length, all bolt hole locations (X, Y position on each face, diameter), all cut conditions (perpendicular, angle, cope), scribing marks (piece mark, paint mark), and any special operations (thread tapping, countersinking). It is a text file formatted to the DSTV87 standard that all major CNC equipment manufacturers support.
Full Explanation
The NC1 file format uses header records (profile name, length, rotation) and operation records for each machining operation (BH = bolt hole, SC = scribing, KO = cope, SA = saw cut). A typical simple beam NC1 file is 20–50 lines; a complex assembly member may have 200+ lines. The machine's CNC controller reads the file sequentially and executes each operation. The file can be viewed and edited in a text editor for verification, though editing should only be done by qualified personnel.
What This Means for Your Shop
Understanding the NC1 file structure allows your CNC operator to quickly identify errors — a wrong hole diameter coded as BH 22 (22mm) instead of BH 22.2 (7/8"), for example, is readable in the file before the machine runs. This is a QC capability that purely GUI-based operators lack.
Common Mistakes
Running NC1 files from the detailer without verifying units. Some detailers work in metric; if your CNC controller is set for imperial units, the file must be converted or the controller configured for metric — otherwise all dimensions are wrong.
Recommended Process
At project kickoff, confirm with the detailer: DSTV file units (metric/imperial), hole diameter notation convention (nominal vs. actual), and any project-specific coding requirements for special operations. Run a test file on a sample member before production.