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AI Connection Detection for Steel Fabrication: Bolts, Copes, and Welds — Automatically

SteelFlo Team3 min read

AI Connection Detection for Steel Fabrication

Steel estimators spend hours extracting connection details from shop drawings by hand. Every bolt count, cope dimension, plate thickness, and weld callout has to be read, recorded, and entered into a spreadsheet. On a 100-page shop drawing set, that is an entire day of tedious work.

SteelFlo now handles this automatically.

What Gets Detected

When you upload a shop drawing PDF, SteelFlo's AI reads every page and extracts:

  • Connection types — shear, moment, base plate, brace, and splice connections
  • Bolt patterns — count, diameter, grade (A325, A490, Grade 8.8, 10.9), and hole type (standard, short slot, long slot, oversized)
  • Cope dimensions — depth, length, and which flange (top, bottom, or both)
  • Plates — shear tabs, end plates, gussets, stiffeners, and base plates with thickness and dimensions
  • Welds — fillet, CJP, and PJP with size and length
  • Studs — shear stud count, diameter, and length
  • Camber — beam camber values detected from callouts

All of this appears in a dedicated Connections tab on the Review page, where you can confirm or reject each detection before it flows into your BOM.

How It Works

The detection runs in two passes:

Pass 1: Text Scan. The system scans every page for connection-related keywords — bolt specs, cope callouts, weld symbols, plate dimensions, hole patterns, and connection type references. Pages with multiple connection indicators get flagged for deeper analysis.

Pass 2: Vision Analysis. Flagged pages are sent to a vision AI model that reads the actual drawing — not just the text, but the geometry. It identifies connection areas, reads bolt patterns from the drawing, and extracts plate and cope details that text alone cannot capture.

The two passes cross-validate each other. If the text scan finds "4-3/4 A325" and the vision model sees 4 bolt holes in the drawing, the confidence goes up. This dual approach catches details that either method alone would miss.

Works on Shop Drawings and Design Drawings

Shop drawings (from Tekla, SDS/2, or other detailing software) contain rich connection data on every member sheet. SteelFlo extracts the full picture — every bolt, every cope, every plate.

Design drawings (engineer's blueprints) have sparser connection info, typically on a few "typical detail" sheets. SteelFlo detects what is there and gracefully reports nothing when connection details are absent. No false positives, no noise.

Hardware Rolls Into Your BOM

Confirmed connections automatically aggregate into a Connection Hardware section on the Export page. If 12 shear connections each use 4 bolts, you see "48x 3/4" A325 Bolts" as a single line item. Plates, studs, and other hardware aggregate the same way.

This feeds directly into pricing. No manual hardware entry. No missed bolts.

International Support

Connection detection handles both US and international specifications:

  • US: A325, A490, A307 bolts, imperial dimensions
  • Metric: Grade 8.8, 10.9, 4.6, M20/M24 bolts, metric dimensions

The same drawing can mix conventions — SteelFlo reads whatever is on the page.

Try It Now

Upload a shop drawing with connection details and see for yourself. The Connections tab appears automatically when connection data is found. Every detection includes the raw text evidence so you can see exactly what the AI read from your drawing.

Start your free trial and upload a shop drawing today.

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