Canadian Welding Bureau (CWB) Level I Practice Exam

Dimensions and units are communicated on the drawing because it is the primary document that defines the exact geometry and size of the part. The welder uses the drawing to know how long, wide, and where features like holes or welds must be placed, and the units are shown directly next to the dimensions or defined in the drawing’s title block notes, ensuring everyone uses the same measurement system (inches or millimeters).

Other documents serve different roles: a welding procedure specification outlines welding variables and process controls rather than the full geometric layout; a bill of materials lists parts and materials; standards provide rules. They do not convey the complete dimensional layout with units the way the drawing does, so the drawing is where the units are typically found.