The Required Information Set
A fabrication-ready shop drawing must contain:
- Piece mark — unique identifier stamped or painted on the member
- Section size and material grade — W14×132 A992, HSS 8×8×1/2 A500-C, PL1×10 A36
- Overall member length, end-to-end, to the nearest 1/16"
- All hole locations — row and column spacing, edge distances, bolt diameter
- Bolt grade and installation method callout — A325-N, A325-X, A490-SC
- Weld symbols per AWS A2.4 — size, length, type, and process
- Surface preparation and coating notes — SSPC-SP6 blast, primer type and color, areas to leave bare for field welds
- All cope dimensions — depth, length, and corner radius where required
What Happens When Information Is Missing
Every missing item on a shop drawing becomes a question on the shop floor. Questions have two outcomes: the shop foreman makes an assumption (which may be wrong), or production stops while the drawing is sent back for revision. Wrong assumptions discovered after fabrication mean rework — cutting off a plate and re-welding, re-drilling a hole pattern, or scrapping a member entirely. The cost of a missing weld callout discovered after a member is assembled and painted is orders of magnitude higher than catching it during drawing QA.
The QA Check Before Release
Before any drawing is released for fabrication, a dedicated QA check should compare the drawing against the model, verify all dimensions are shown, confirm hole patterns match the connection design, and check that the revision block and drawing number are correct. At Tectonix, QA checks are performed by a project team member who did not produce the drawing — the same practice used by structural engineering firms to catch self-review blindness.