Direct Answer
Design drawings show what the structure should do — member sizes, span lengths, loading diagrams, and connection types selected by the engineer. Shop drawings show how to build each individual piece — exact cut lengths, hole patterns, weld symbols, piece marks, and material lists. They serve different audiences: engineers review design drawings for code compliance; fabricators work from shop drawings on the shop floor.
Full Explanation
A design drawing might show 'W12×53 beam, bolted shear tab connection' at a given framing line. The corresponding shop drawing for that beam shows its exact length (accounting for setbacks from column faces), the shear tab dimensions, the bolt hole pattern (diameter, spacing, edge distance), the welds attaching the shear tab to the web, and its unique piece mark. Shop drawings are produced by the steel detailer using the design drawings as input. They must be reviewed and approved by the engineer before fabrication.
What This Means for Your Shop
Never use design drawings as fabrication documents. They lack the precision needed for your saws, drills, and welders. Using design drawings directly is among the top causes of field fit-up failures.
Common Mistakes
Printing design drawings at a different scale and using them to verify member lengths. Design drawing dimensions are nominal; shop drawing dimensions are actual.
Recommended Process
Maintain a strict separation between design drawings (engineering reference) and shop drawings (fabrication documents). Tag each drawing set clearly and control distribution so shop floor personnel only have access to approved shop drawings.