On most commercial steel projects, the Structural Engineer of Record (SER) does not design every connection. They show the required forces on the structural drawings and delegate the connection design to the fabricator's engineer. The fabricator's engineer designs the connection per AISC 360-22 Chapter J, stamps the calculations, and produces the AISC 303-22 shop drawings that go back to the SER for approval. This article walks through how the three documents fit together, what each connection type requires, and what plan check actually looks for.

The three governing documents

  • AISC 360-22 — Specification for Structural Steel Buildings. Member design (Chapters D–I) and connection design (Chapter J — bolts, welds, affected elements).
  • AISC 303-22 — Code of Standard Practice. Shop drawing content, mill and fit-up tolerances, division of responsibility between SER, fabricator, and erector.
  • AWS D1.1 — Structural Welding Code, Steel. Prequalified WPS, weld symbols (per AWS A2.4), inspection, and weld acceptance criteria.

On Seismic Design Category D–F projects, add AISC 341-22 (Seismic Provisions) and AISC 358-22 (Prequalified Moment Connections for SMF/IMF). For high-strength bolts, add the RCSC 2020 Specification.

Connection types — what to design and check

Shear tab (single-plate) connections — AISC 360-22 §J4

The workhorse beam-to-column shear connection. Check bolt shear, plate shear yield and rupture, plate block shear, weld to the supporting member, and the supporting member's local response. For skewed and sloped connections, account for prying.

Double-angle and end-plate connections

Double angles handle higher shears than single shear tabs. End-plate connections (extended or flush) are common for moment-resisting beams; design per AISC Manual Part 12 with bolt prying per §J3.6.

Moment connections (AISC 358-22 prequalified)

For SMF and IMF, use one of the prequalified types: RBS (Reduced Beam Section), BFP (Bolted Flange Plate), WUF-W (Welded Unreinforced Flange-Welded Web), or End-Plate. Each type has prequalification limits (beam depth, span-to-depth, bolt grade) — exceed them and the connection requires project-specific cyclic testing per AISC 341 §K.

Brace gusset plates — Whitmore + Uniform Force Method

For SCBF and OCBF brace connections, design the gusset using the Uniform Force Method (AISC Manual Part 13) and check Whitmore section yielding, gusset buckling, weld capacity, and the beam/ column local response. AISC 341 §F2.6 requires the connection to develop the expected brace tension capacity (RyFyAg) with a 2.0% drift accommodation. Complex gusset geometries are commonly verified with finite element analysis services when the Whitmore strip oversimplifies the load path.

Column base plates — AISC Design Guide 1 + ACI 318-19 Ch. 17

Base plate thickness is sized for the cantilever bending under bearing pressure. The anchor rods are designed per ACI 318-19 Chapter 17 — tension, shear, concrete breakout, pull-out, and side- face blowout — with Ω0 amplification on concrete- controlled limit states for SDC C+. See our ASCE 7-22 Chapter 13 guide and anchor bolt design examples for the anchorage detail.

What an AISC 303 shop drawing must contain

  • Plan, elevation, and section views of each assembly with piece marks.
  • Single-part details for every cut piece — length, material grade, hole pattern, weld preparation.
  • Bolt schedule with grade (A325/F3125, A490, A307), diameter, length, and pretension status (snug, pretensioned, slip-critical per RCSC).
  • Weld symbols per AWS A2.4 with size, length, type, and process callout.
  • Anchor bolt setting plan with diameter, projection, embedment, and tolerance.
  • Erection drawings with piece marks, field bolt schedule, and reaction arrows.
  • Bill of materials with mill cert tracking.

CNC and the modern shop floor

Most AISC-certified shops run a beam line, drill line, and coper from CNC files. The detailing software (SDS/2, Tekla, Advance Steel) exports DSTV/NC1 files that drive the machinery directly — saving the layout person from re-marking every hole. A complete shop package includes the PDF drawings, DWG/DXF for shop markup, and DSTV/NC1 for the machines.

Welding — prequalified WPS vs project-qualified

AWS D1.1 Clause 5 prequalifies most common joints in carbon steel with SMAW, GMAW, FCAW, and SAW processes. A prequalified WPS bypasses the PQR (Procedure Qualification Record) requirement — saving days of test plates and paperwork. Project-specific qualification is required for unusual base metals, exotic positions, or weld geometries outside Clause 5 limits.

Special inspection per IBC Chapter 17

  • High-strength bolting: visual inspection per RCSC; periodic on snug-tight, continuous on pretensioned.
  • Welding: continuous inspection on CJP groove welds and SMF/IMF moment connections; periodic on fillets ≥ 5/16″.
  • Anchor rods: verification of placement before concrete pour and pretension after cure.
  • Steel frame structural integrity: braced and moment frame connections require a final inspection per IBC §1705.2.

Common mistakes that fail SER review

  • Calculations sized to the beam reaction shown on the plan rather than the maximum reaction allowed by the AISC tables when the SER omitted the reaction.
  • Forgetting to design the supporting column web for the shear tab's eccentric reaction.
  • Using a snug-tight bolt where the SER spec calls for slip-critical.
  • Detailing a brace gusset without checking the Whitmore buckling limit state.
  • Sizing column anchor rods for tension only without checking Ω0-amplified concrete breakout.
  • Shop drawings missing the AISC 303 erection plan or anchor bolt setting plan.

How PANACHE ENGINEERING delivers steel packages

We provide PE-stamped delegated connection design and AISC 303 shop drawings for fabricators across the country — including miscellaneous steel (stairs, platforms, dunnage), seismic-rated equipment supports, and HCAI/OSHPD hospital projects. See our structural steel fabrication services page, browse more articles in our structural steel connection design hub, or contact our steel design team with the S-sheets and a tonnage estimate for a fixed-fee quote in 48 hours.