AISC Was Just the Starting Point
When we launched Steelflo, every detection pattern was tuned for American steel — W-shapes, HSS, channels, angles, pipes, and plates in AISC notation. That's what most US fabricators work with, and it's where we started.
But structural steel isn't an American-only trade. Fabricators in the UK use UC and UB sections. European shops work with HEA, HEB, and IPE profiles. Australian estimators see 310UB40.4 and 150PFC on their drawings. And many projects — especially international ones — mix standards on the same drawing set.
As of April 2026, Steelflo supports four major steel naming standards, with automatic detection that routes each drawing to the right pattern library. No manual configuration needed.
The Four Standards Steelflo Supports
AISC (United States)
The standard most US fabricators know. Wide flanges as W12X26, hollow structural sections as HSS6X6X1/4, channels as C10X15.3, angles as L4X4X1/2. Imperial units throughout — weights in pounds per linear foot, dimensions in inches.
Steelflo has 26 detection patterns covering every AISC shape category, validated against real fabrication drawings.
EN (European)
European structural sections follow a different naming convention entirely. Instead of "W" shapes, European drawings call out HEA, HEB, and HEM profiles. Instead of channels, you see UPN and IPN. Instead of wide flanges, there are IPE beams and HD columns.
Steelflo recognizes HEA200, HEB300, HEM400, IPE270, IPE600, UPN120, IPN180, and HD400 — with 8 detection patterns covering the major European profile families. Metric output: weights in kilograms per meter, dimensions in millimeters.
These patterns also fire on UK drawings, which frequently mix BS sections (UC, UB) with European profiles (IPE, HEA) on the same sheet.
BS/IS (United Kingdom, India, Middle East)
British and Indian standard sections use a distinctive format: UC305×305×158 for universal columns, UB610×229×101 for universal beams, SHS220×220×6 for square hollow sections. The multiplication sign between dimensions is a dead giveaway.
Steelflo has 10 detection patterns for BS/IS sections, including UC, UB, SHS, RHS, CHS, PFC, plate girders, and angles. The pipeline also decodes structured member IDs common in Indian fabrication drawings — codes like 01-STR-06-VBR018 get parsed to identify the member as vertical bracing.
AS/NZS (Australia, New Zealand)
Australian and New Zealand sections put the number first: 310UB40.4 instead of W12X26, 250UC89.5 instead of W10X49. Parallel flange channels show up as 150PFC rather than C6X8.2.
Steelflo has 11 detection patterns for AS/NZS notation, with weight lookups from a dedicated database of 55+ section profiles. All output in metric.
How Auto-Detection Works
You don't tell Steelflo which standard your drawing uses. The pipeline figures it out.
When you upload a PDF, the text extraction pass scans every page and counts signature matches against each standard's pattern library. AISC patterns look for W-shapes and HSS. EN patterns look for HEA/HEB/IPE. BS/IS patterns look for UC/UB with multiplication signs. AS/NZS patterns look for the number-first format.
The standard with the highest match count wins, and the pipeline routes to that standard's full regex library and weight database. The detection results include the identified standard, a confidence score, and the unit system used.
On real drawings this works reliably because each standard's naming convention is distinctive enough that false-positive crossover is rare. A drawing full of UC305×305×158 callouts is not going to be mistaken for AISC.
Weight Lookups by Standard
Detection is only half the job. Once Steelflo identifies a member, it needs the section weight for BOM generation and pricing.
Each standard routes to its own weight database:
- AISC: Hardcoded lookup table covering 550+ sections, weights in pounds per linear foot
- EN and BS/IS: ArcelorMittal section database with 1,104 profiles, weights in kilograms per meter
- AS/NZS: Dedicated database of 55+ sections, weights in kilograms per meter
Metric weights get converted to imperial (kg/m × 0.67197 = lbs/ft) so the downstream pricing engine works consistently. If you're working in metric, the UI displays metric values — the conversion happens behind the scenes.
What This Means for International Fabricators
Before multi-standard support, the options for AI-assisted steel takeoff outside the US were limited. Most tools — including competitors like Beam AI — are built around US conventions and AISC notation. If you handed them a drawing full of HEA200 and UPN120 callouts, you'd get nothing back.
Steelflo treats international standards as first-class citizens, not afterthoughts. The same pipeline, the same verification workflow, the same export options — just with detection patterns and weight data tuned for your standard.
If you're a fabricator in the UK, Europe, Australia, New Zealand, India, or the Middle East, your drawings work in Steelflo today. Upload one and see. For standard-specific deep dives, check out our guides on European steel sections (HEA, HEB, IPE) and steel takeoff for Australian and NZ fabricators.
Validated on Real Drawings
We don't ship detection patterns without testing them on actual fabrication drawings. Here's what we've validated:
- AISC (US): Hutchings job — 53 detections, 18 member types, every type confirmed against the estimator's hand count
- BS/IS (India): Jotun convention center — 1,047 detections across a large drawing set, including decoded member IDs for bracing, top chords, and bottom chords
- AS/NZS (Australia): WW Austral (119 detections) and BMW Penrith (237 detections) — both validated against known member lists
- EN (Europe): UK hybrid drawing — 155 detections including 14 IPE160 members mixed with BS sections on the same sheets
These aren't synthetic test files. They're real drawings from real projects.
What Standards Does Steelflo Support?
Steelflo supports AISC (US), EN (European), BS/IS (UK, India, Middle East), and AS/NZS (Australia, New Zealand). The pipeline auto-detects which standard a drawing uses and routes to the correct detection patterns and weight database.
Do I Need to Tell Steelflo Which Standard My Drawing Uses?
No. The auto-detection system scans all pages, identifies signature patterns for each standard, and selects the best match automatically. You upload the PDF and the pipeline handles the rest.
Can Steelflo Handle Drawings That Mix Standards?
Yes. UK drawings commonly mix BS sections (UC, UB) with European profiles (IPE, HEA) on the same sheet. Steelflo's EN patterns are included in the BS/IS detection route specifically to handle this.
Does Steelflo Support Metric Units?
Yes. EN, BS/IS, and AS/NZS drawings produce metric output — weights in kilograms per meter, dimensions in millimeters. AISC drawings produce imperial output. The unit system is determined by the detected standard.
What If My Standard Isn't Supported Yet?
If you're working with a steel naming convention that Steelflo doesn't recognize, reach out. Each new standard is a set of regex patterns plus a weight lookup table — expanding coverage is something we do regularly based on user demand.
Try It on Your Drawings
The best way to test multi-standard support is to upload one of your own drawings. Steelflo's free tier gives you one AI takeoff — enough to see if your standard is detected correctly and your members are identified.
Start free at steelfloai.com.