Structural steel shop drawings are the bridge between the SER's S-sheets and the cutting torch on the shop floor. They have to be accurate enough to drive a CNC drill line, complete enough to satisfy the SER's review, and fast enough to keep mill order lead times in sync with the construction schedule. AISC 303-22 governs every step. Here's the real workflow — what happens, who is responsible, and where projects usually slip.
Step 1 — Contract award and S-sheet takeoff
Once the fabricator is awarded, the detailer (in-house or subcontracted) takes off the structural drawings and produces:
- An Advance Bill of Material (ABM) — every rolled section, plate, and bolt grade and quantity needed to place mill orders
- A preliminary erection plan showing piece marks at every column and beam location
- A connection schedule listing every shear, moment, and brace connection that needs delegated design
The ABM goes to the mill within 1–2 weeks of award because rolled sections (especially heavy W-shapes and HSS) carry 6–12 week lead times from US mills and longer from imports.
Step 2 — RFI cycle
No structural drawing set is complete enough to detail without questions. Typical first-round RFIs:
- Missing or inconsistent connection forces (shear, axial, moment) on the connection schedule
- Beam top-of-steel elevations conflicting with slab or deck thickness
- Brace gusset clearance with adjacent beam flanges or column webs
- Anchor rod pattern conflicts with concrete reinforcing
- Field-fit conditions where steel meets existing construction
- Camber values for long-span beams not specified
AISC 303 §4.4 puts RFI response on the SER's clock. A 5-day SER response window is typical; longer windows compress detailing into the fabrication float and risk delaying the first shop drawing submittal.
Step 3 — Delegated connection design (when applicable)
If the structural drawings show connection forces and reference "design by fabricator," the fabricator's engineer designs every connection per AISC 360-22 Chapter J — shear tabs, single-plate and double-angle clips, end plates, brace gussets, base plates, splices. For seismic SCBF, OMF, SMF, and EBF connections in SDC D–F, AISC 341-22 governs and AISC 358-22 prequalifies the moment connection types (RBS, BFP, ConXL, etc.). The connection calculations are PE-stamped and submitted alongside (or just ahead of) the shop drawings.
See our companion article on AISC 360-22 connection design and shop drawings for the connection design side of this workflow.
Step 4 — Detailing in 3D
Modern detailing happens in Tekla Structures or SDS/2. The detailer builds a 3D model of every piece — including connections, holes, copes, weld preparations, and erection marks. The model automatically generates:
- Erection drawings — plan and elevation views with piece marks, bolt sizes, and field welds called out per AWS A2.4
- Single-part details — every unique piece mark drawn at scale with all dimensions, holes, copes, welds, and material grade
- Assembly drawings — shop-welded subassemblies (e.g., column with shear tabs)
- Anchor rod setting plan — for the GC to set anchor rods before steel arrives
- Bill of materials — feeds the cutting nest and the shop's ERP system
- CNC files — DSTV/NC1 files driving the drill lines, beam saws, and plasma tables
Step 5 — Internal checking
Before submittal, a senior checker reviews every drawing against the S-sheets, the connection calculations, and the model. Common catches:
- Piece marks duplicated or missing
- Hole patterns rotated 180° on symmetric pieces
- Bolt grades mismatched between erection and single-part drawings
- Weld symbols missing the AWS process callout
- Mill orders not matching the ABM (wrong length tolerance, wrong grade)
Step 6 — SER review and the meaning of "approved"
Shop drawings go to the SER for review — typically a 10-business-day review per AISC 303 §4.4. The SER returns one of:
- Approved — release for fabrication
- Approved as Noted — release for fabrication with the noted corrections incorporated
- Revise and Resubmit — corrections required, no fabrication
- Rejected — major scope or design issue, do not fabricate
Critically, AISC 303 §4.5 is explicit: SER approval does not transfer responsibility for the accuracy of the shop drawings back to the SER. The fabricator and detailer remain responsible for dimensional accuracy, fit-up, and faithful execution of the design intent.
Step 7 — Released for fabrication
Approved drawings flow to the shop floor. The model's CNC files drive the drill line, beam saw, plasma cutter, and coping machine. Welders work from the single-part drawings. QC inspectors (typically AWS Certified Welding Inspectors) sign off welds against the WPS and the AWS D1.1 visual acceptance criteria. NDT (UT for full-penetration welds, MT for fillets in seismic frames) is performed and reported.
Step 8 — As-built and erection support
After erection, the detailer issues as-built drawings reflecting any field-modified pieces. The fabricator's engineer responds to field RFIs (member miscut, hole misalignment, welder qualification records) until punch list closeout.
Where projects slip
- Slow SER response to first-round RFIs (compresses detailing into mill float)
- Connection forces missing on the structural drawings (forces multiple RFI rounds)
- Owner-driven scope changes after mill orders are placed (rolled section returns are expensive)
- HCAI or GSA projects without a pre-submittal coordination meeting (special inspection requirements not surfaced until review)
- Inadequate model coordination with MEP (penetrations and embeds discovered after fabrication)
How PANACHE ENGINEERING delivers shop drawings
We produce AISC 303-compliant shop drawings and PE-stamped delegated connection design as part of single-source steel packages — design, detailing, and managed fabrication through AISC Certified partner shops, nationwide. See our structural steel fabrication services page, read our companion guide on AISC Certified Fabricator endorsements, or contact our team with your S-sheets and a tonnage estimate for a fixed-fee quote in 48 hours.