CDT Structural & Mechanical Drafting Flashcards

Which projection method is standard in the United States for engineering drawings?

Answer: Third-angle projection

Third-angle projection is the standard method used in the US, where the view is placed on the same side as the observer relative to the part.

What does a centerline (alternating long and short dashes) represent on a mechanical drawing?

Answer: The axis of symmetry or center of a circular feature

Centerlines mark the axis of symmetry of a part, the center of holes or cylinders, or the pitch circle of bolt patterns.

A bill of materials (BOM) on a mechanical assembly drawing typically includes which information?

Answer: Item number, part number, description, quantity, and material

A BOM is a structured list that includes each item's number, part number or drawing number, description, quantity required, and often material specification.

In structural drafting, what does a break line indicate?

Answer: That a long part has been shortened and the middle portion removed from the view

Break lines are used when a long uniform object is too large to draw at full scale; the middle is removed and the ends are brought together with a break symbol.

What is a revision block (revision history) on an engineering drawing used for?

Answer: Tracking changes made to the drawing after initial release

The revision block records each change made to the drawing after release, including the revision letter/number, description of change, date, and approver.

Which line type on a structural or mechanical drawing indicates an alternate position or a repeated feature?

Answer: Phantom line (long-short-short dashes)

Phantom lines are used to show alternate positions of moving parts, repeated details, or the outline of adjacent parts for reference.