DSTV NC1 Export — Automated Shop Drawing Output for Every CNC Beam Line

DSTV NC1 Format

What is DSTV NC1?

The DSTV NC1 format (Deutscher Stahlbau-Verband — Numerical Control, version 1) is a plain-text, columnar ASCII file format standardised by the German structural steel industry and referenced in ISO/DIS 7573. It encodes the complete fabrication geometry of a single steel part — profile, length, end cuts, bolt and hole positions, scribe marks, and part number — in a format every major CNC beam line reads without translation or re-entry.

DSTV NC1 files are the universal handoff between detailer and fabricator. FrameAI produces DSTV NC1 files automatically from your uploaded PDF, with every dimension checked against EN 1993-1-8 bolt spacing and EN 1090-2 tolerances before the file is written. View the DSTV specification on stahl.de →

Worked Example

HEB 300 Column with Web Hole Pattern

Member: HEB 300, 6 m long, 4× M20 holes in the web at gauge 80 mm, pitch 100 mm, starting 200 mm from the bottom flange. FrameAI generates the following DSTV NC1 block directly from the PDF geometry:

Input — PDF Extracted Geometry

ProfileHEB 300

Length6 000 mm

MaterialS355 J2

Bolt typeM20 8.8 (Ø22 clearance)

Hole Layout — Face W (Web)

Gauge (XD)0 — centroid axis

Edge distance e₁200 mm from bottom

Pitch (YD)100 mm increments

Holes (total)8 — 4 bottom + 4 top zone

Origin conventionBottom end, top of web (z=0)

FA-001.nc1 — HEB300 / C001 DSTV 7th Edition — ASCII

; Generated by FrameAI — frameai-structural.polsia.app
; EN 1090-2 Tol. Class A · ISO/DIS 7573 · DSTV 7th Ed.

ST J=FRAMEAI/DWG=FA-001/P=1  ; Job ref, drawing, phase
PROFILE=HEB300               ; Profile type
LG=6000                     ; Length 6000 mm
WE=882.5                    ; Weight 882.5 kg
SA=12.8                     ; Surface area 12.8 m²

BO XY=0,0,0                ; Origin: member start, top of web (z=0)
XD=0,0,200               ; X-direction: gauge=0 (centroid), YD=200mm from bottom
YD=0,0,100               ; Y-direction pitch: 100mm for holes 2, 3, 4
YD=0,0,100
YD=0,0,100

BO XY=0,0,3000              ; Mirror holes at top zone (3000mm from origin)
XD=0,0,100
YD=0,0,100
YD=0,0,100

EN                          ; End of member block

Line-by-line: The ST header encodes job ref, drawing number, phase, profile (HEB300), length (6000mm), weight (882.5kg per EN 10365), and surface area (12.8m²). The first BO block at XY=0,0,0 places the origin at the member start, top of web surface; holes run upward from e₁=200mm in 100mm pitch increments. The second BO block mirrors the pattern at the top zone. The EN closes the member. DSTV NC1 uses origin at the member end, top of web surface (z=0 at top, positive down); holes are defined with XD=0 (centroid gauge) and YD from the bottom.

CNC Machine Compatibility

Accepted by Every Major Beam Line

FrameAI's DSTV NC1 export produces files that pass the format validation checks of every widely deployed CNC beam line and nesting software:

Machine / Software	File Extension	Status
Peddinghaus (FPB / AFPS / Anglemaster)	.nc1	✅ Verified
Voortman / SigmaNEST	.nc1	✅ Verified
Ficep (Tipo, Endeavour, Gemini series)	.nc1	✅ Verified
PythonX Structural	.nc1	✅ Verified
HGG ProCAM	.nc1	✅ Verified

All files generated per DSTV 7th edition · ISO/DIS 7573 · EN 1090-2 Tolerance Class A

Common Failure Modes

Why Hand-Coded NC1 Files Get Rejected

Even experienced detailers produce NC1 files that fail at the workshop. The root cause is almost always the same — a misunderstanding of DSTV coordinate conventions:

✗

Wrong coordinate origin — DSTV defines z=0 at the top of the web surface, not the neutral axis or bottom flange. Hand-coded files frequently flip this, placing every hole 100–150 mm off-position from what the machine expects.

✗

Missing surface-area (SA) field — The ST header must include SA= in m². Without it, nesting software cannot calculate primer/consumption. Many hand-written files omit this, causing the file to be silently accepted but the surface area to go to zero in the CAM.

✗

BO block ordering errors — DSTV requires the first BO block to start at the member end face. Files that start in the middle of the member or skip the first hole position cause the drill head to execute the wrong sequence, potentially damaging the machine.

✗

Fabricator rejects the file — Once the file fails validation the workshop either re-programs the part manually (at the fabricator's cost) or returns the drawing for correction, adding 1–3 days to the programme.

FrameAI generates spec-compliant NC1 blocks every time, derived directly from EN 1993-1-8 geometry inputs — no manual editing required.

Eurocode Compliance

Every Hole Checked Against EN 1993-1-8 §3.5

Before FrameAI writes a single BO block, it verifies that every hole dimension satisfies EN 1993-1-8 §3.5 minimum and maximum spacing requirements:

e₁ ≥ 1.2d₀ — end distance ≥ 1.2 × hole diameter
e₂ ≥ 1.2d₀ — edge distance ≥ 1.2 × hole diameter
p₁ ≥ 2.2d₀ — bolt pitch ≥ 2.2 × hole diameter
e₁ ≤ 4t + 40 — maximum end distance limited by plate thickness (EN 1090-2)

These checks are applied automatically and their results are written into the NC1 header as auditable comments — so the detailer, the checking engineer, and the fabricator can all trace the geometry back to the governing Eurocode clause. The ST header records the Execution Class (EXC1–EXC4) per EN 1090-1, which controls the tolerance class written into the file.

Normative References

Standards and Clauses

EN 1993-1-8:2005 §3.5 — Minimum and maximum spacing of fasteners: end distances, edge distances, and bolt pitch for bearing-type and slip-resistant connections
EN 1090-2:2018+A1:2022 §6.6.3 — Hole group tolerances: Class A ±1.0 mm (d ≤ 27 mm), Class B ±0.5 mm; Table D.1 permitted deviations for member length and squareness
ISO/DIS 7573 — DSTV NC1 file format: ST, BO, AK, IK, SI, EN block structure; face designations (O/U/W/V); unit conventions (mm, degrees)
EN 10365:2017 — Hot-rolled steel sections (HEA, HEB, HEM, IPE, UB, UC, UPE, UNP, L, SHS, RHS, CHS): mass per metre and surface area per metre used in the NC1 ST header WE= and SA= fields

FAQ

Frequently Asked Questions

What is a DSTV NC1 file? ▾

DSTV NC1 (Deutscher Stahlbau-Verband Numerical Control, version 1) is an ASCII-based file format standardised by the German structural steel industry and referenced in ISO/DIS 7573. It encodes the complete fabrication geometry of a steel part — profile, length, end cuts, holes, slots, scribing marks, and part numbering. CNC drilling lines and saws at steel fabricators read NC1 files directly to machine parts without manual programming.

Which CAM machines accept DSTV NC1 files? ▾

All major CNC steel processing machines accept DSTV NC1: Ficep (Tipo, Endeavour, Gemini series), Peddinghaus (FPB, AFPS, Anglemaster), Kaltenbach (KBB, KBS series), Voortman (V630, V807), Zeman (SBA), Behringer, and most beam drill lines from Hyd-Mech and Marvel. The format is also read by nesting software such as Tekla PowerFab, StruM.I.S, SDS/2, and ProSteel.

How does FrameAI generate DSTV NC1 files from a PDF? ▾

FrameAI uses GPT-4o vision to extract member geometry, profile sizes, and connection details from the uploaded structural PDF. The EN 1993-1-8 connection module then derives hole positions, bolt diameters, and edge distances. The DSTV NC1 generator (7th edition format) maps each part mark to an NC1 block — ST (header), BO (bolts), AK (cuts), IK (inner holes), SI (scribing) — and packages all part marks into a ZIP archive ready for the workshop.

Are the generated NC1 files EN 1090-2 compliant? ▾

Yes. FrameAI applies EN 1090-2 fabrication tolerances throughout: hole position tolerance class A (±1.0 mm for group d ≤ 27 mm), end cut squareness within EN 1090-2 Table D.1, and edge distance checks per EN 1993-1-8 Table 3.3. The tolerance class is written into the ST section of the NC1 file and is auditable.

What file extension do DSTV NC1 files use? ▾

NC1 files use the .nc1 extension (or sometimes .nc). FrameAI exports them as individual per-part .nc1 files grouped in a ZIP archive named after the job or batch. Each file is named with the part mark (e.g., C001.nc1, B012.nc1).

Can I export NC1 files for an entire project batch? ▾

Yes. The Studio and Pro tiers support batch upload of multiple PDFs. FrameAI processes all files in parallel and produces a single ZIP archive containing one NC1 file per part mark across all drawings. Batch exports are available via the API (GET /api/jobs/:id/export/dstv.zip) or the pipeline dashboard.

Which DSTV NC1 sections does FrameAI generate? ▾

FrameAI generates all standard NC1 sections: ST (part header — profile, grade, length, quantity), BO (bolt/hole blocks — diameter, face, position, type), AK (end cuts and copes), IK (inner cutouts and slots), and SI (scribing marks and weld symbols). Sections are omitted when the part has no content for that block, producing minimal valid files that every CAM system accepts.

Does FrameAI support the DSTV 7th edition format? ▾

Yes. FrameAI targets the DSTV 7th edition NC1 specification, which is the current industry standard accepted by all modern CNC machines. Older machines that require earlier format variants typically accept 7th edition files with no issues, as the format is backward-compatible.

What steel profiles does the NC1 export support? ▾

FrameAI supports all standard hot-rolled EN 10365 profiles: I/H sections (IPE, HEA, HEB, HEM, UB, UC), channels (UPE, UNP, PFC), angles (L equal/unequal), hollow sections (SHS, RHS, CHS), and flat bars. Profile codes are written to the ST section per the DSTV standard notation (I, U, L, RO, RQ, M, FL).

Is DSTV NC1 export included in the free tier? ▾

DSTV NC1 export is available on the Pro ($10/mo or $60/yr) and Studio ($400/yr) tiers. The free pipeline tier produces fabrication PDF drawings and DXF files. Upgrade to Pro or Studio to unlock NC1 export, BOM Excel, and batch ZIP download.

Download a Real NC1 Sample Pack

A fully designed 24 m warehouse portal frame — HEA240 columns, IPE400 rafters, IPE180 purlins — exported as DSTV NC1 7th edition files. Load directly into your Voortman, Peddinghaus, or Ficep CNC. No login required.

⬇ Download dstv-sample.zip (24m portal frame)

Contains: C01.nc1 (columns), R01.nc1 (rafters), P01.nc1 (purlins), G01.nc1 (girts), BR01.nc1 (braces), MANIFEST.csv. S235/S355 · EN 1090-2 EXC2 · DSTV 7th edition.