Table of Contents
1. Introduction
“Shop Drawings are drawings, diagrams, schedules, and other data specifically prepared for the work by the contractor, subcontractor, sub-subcontractor, manufacturer, supplier, or distributor, illustrating how specific portions of the work shall be fabricated and/or installed.”
2. Purpose of shop drawings
Fabricator
Transfers information from the Contract Documents into accurate and complete shop and erection drawings with the help of steel detailers.
Erector
Develops the erection sequence of the steel frame, making sure the structure is safely and economically erectable.
EOR
Confirms that the structural steel system is in conformance with the intent of the structural design and the contract documents.
Architect
Reviews the shop drawings for general conformance with the contract documents.
General Contractor
Confirms that the structural steel is in general conformance with the Contract Documents and contractor agreement and to also coordinate with the other affected trades.
3. Best practices to be followed
✅ Always adhere to the standards: Familiarize yourself with AISC (American Institute of Steel Construction), AWS (American Welding Society), OSHA (Occupational Safety and Health Administration), and the project-specific detailing standards.
✅ Keep drawings presentable: Lettering should be clean and legible. Remember, shop workers often read drawings in less-than-ideal conditions.
✅ Use universal symbols and notations: Symbols and conventions should be industry-standard, to ensure easy understanding across teams and disciplines.
✅ Leverage technology: Utilize the latest detailing software and automation tools for speed, accuracy, and error reduction.
✅ Ensure clarity: Avoid cluttered sketches. Place general notes near the title block, and position section views in consistent directions.
✅ Weld detailing: Always apply ANSI / AWS welding symbols correctly. Include type, size, location, and special requirements.
✅ Paint notes and galvanizing considerations: Be clear about painting requirements. Never mix painted and unpainted parts on the same drawing.
✅ Learn from past projects: Review prior project successes and failures to improve your detailing strategy.
4. Common mistakes
❌ Deviating from client standards and requirements
❌ Member orientation errors
❌ Incorrect reference dimension (RD) start point and dimension pick points
❌ Missing dimensions and weld details
❌ Incorrect or missing part marks
❌ Wrong weld symbols and incorrect skewed weld details
❌ Wrong weld designation for pre-qualified welds
❌ Using text-based references instead of associative part marks
❌ “Exploded” dimensions after model updates
❌ Overlapping or cluttered dimensions
❌ Uncoordinated section views or conflicting notes
❌ Missing slopes and skewed dimensions
❌ Improper scaling or view alignment in drawing layouts
How to rectify those mistakes
These issues may seem small, but they can result in significant delays, cost overruns, or field rework. The detailer plays a key role in preventing these issues by accurately providing all required information along with the help of checklists. Diligent checking is also the key to prevent them.
The checker reviews everything the detailer produces, from bills and bolt lists to drawings, making sure all details like quantities, material descriptions, dimensions, and specifications are accurate. The checker carefully verifies each detail to ensure that there are no errors, standard procedures were followed, and all drawings are in full compliance with the contract documents.
5. A checklist for shop drawings ✅
- Drawing number and title block details
- Text precision, font type and text height
- Print layout per client standard
- Reference dimension (RD) start point
- Locating dimensions
- Part marks and weld symbols
- Cross sections and detail views where required
- Slopes and skewed dimensions
- Pre-qualified weld designations per codes and client standards
- Hole details (standard, slotted, oversized), size, and spacing
- Section mark co-ordination
- Dimensions overlapping or exploded dimensions
- Drawing scale and view clarity
- Spelling and grammatical accuracy
- Client/ project standard notes and special notes
- Galvanizing/painting details and notes
- Clearly marked ‘No paint’ areas
- Check for duplicated or missing parts across sheets
- Bill of Materials (BOM) checked for accuracy and completeness
6. Conclusion
Whether the project is a simple warehouse or a complex stadium, every model and drawing should always follow the highest standards of precision and accuracy, as the heart and soul of steel detailing lies in attention to detail and accuracy.
Each detail should be so thoughtfully crafted that anyone reading the drawings can envision the structure as if it were already standing before them.
Steel may stand for decades, but the precision behind it begins with the shop drawings.
Reference:
- Engineering journal / third quarter / 2004-structural steel detailing practices—good and bad by Hugh Dobbie
- Suggestions for Improving the Structural Steel Shop Drawing Process_May 2006
- Structural welding code by American Welding Society (AWS)
- American Institute of Steel Construction (AISC), Detailing for Steel Construction
- Impact of the Shop Drawings on the Accuracy of Estimated Cost of Construction Projects by Hadeer N. Migahed, Ibrahim M. Mahdi, Ibrahim Abdul Rashid
Very well explained about the need of accurate shop drawings. There is no limit set to excel. Keep going Parvathy. Best wishes.