Automating Shop Drawing Takeoffs
Shop drawings are the most detailed documents in steel fabrication. Every member gets its own sheet with exact dimensions, connection details, hole patterns, plate callouts, and weld specifications. A 200-page set from Tekla or SDS/2 contains everything a fab shop needs — but extracting that data into a usable BOM is painfully manual.
The Manual Process
An estimator opens the PDF, flips through every page, and records:
- The member type and size (W410X38.8, C250X30, L100X100X10)
- Quantities from the parts list or piece marks
- Connection hardware at each end — bolt count, bolt grade, plate sizes
- Cope dimensions where members intersect
- Weld specifications
- Any special requirements (camber, studs, special finishes)
On a 183-page set, this takes a full day. On a rush job, it does not get done properly.
What AI Can Do Now
SteelFlo processes the entire shop drawing set in minutes:
Member detection reads every page and identifies steel sections by their AISC, EN, BS, AS/NZS, or GB designation. It handles both label callouts on drawings and verbose parts list formats like "AISC - W 4" x 13" found on equipment detail sheets.
Connection detection identifies shear tabs, moment connections, base plates, bolt patterns, cope dimensions, plate thicknesses, and weld specifications. Each connection is linked to its parent member so you know which beam has which hardware.
Camber detection reads camber callouts near member labels and attaches the value to the correct member.
Everything appears in a review interface where you confirm or reject each detection. Nothing goes into the BOM without your approval.
Tekla Shop Drawings Specifically
Tekla Structures exports follow a consistent format:
- Title block with piece mark (FRB36, COL-12), section size, quantity, and weight
- Parts list with plate sizes, bolt hole counts, and weld lengths
- Drawing views showing the member with connection details at each end
- Section cuts showing cope profiles and stiffener plates
SteelFlo reads all of this. The piece mark identifies the member, the parts list provides hardware quantities, and the drawing views give connection geometry. The vision AI cross-references the text data with the visual layout to catch details that either source alone might miss.
The Output
After review, you get:
- Steel BOM — every member with type, quantity, length, weight, and category
- Connection hardware — bolts, plates, studs, and anchors aggregated by specification
- CSV export — both sections in a single download, ready for your ERP or procurement system
- Pricing — material costs calculated from real market rates with your shop's markup
From a Day to Minutes
A 183-page Tekla shop drawing set that takes 8 hours by hand takes minutes with SteelFlo. The AI handles the counting. You handle the judgment calls.
Upload a shop drawing and see the difference.