Blueprint Reading Flashcards

On a lubrication diagram, a filled black triangle symbol typically represents:

Answer: A grease fitting or lubrication point

A filled triangle symbol on lubrication diagrams marks a grease fitting or oiling point where lubricant should be applied.

The term 'bilateral tolerance' means that the tolerance is applied:

Answer: Equally in both the plus and minus directions from the nominal

Bilateral tolerance distributes the allowable variation equally above and below the nominal dimension, such as ±0.005.

On a ladder logic diagram used for PLC programming, a normally closed contact symbol is represented by:

Answer: Two vertical lines with a diagonal slash between them

A normally closed (NC) contact in ladder logic is shown as two vertical lines with a diagonal slash, indicating it passes current when its coil is de-energized.

A break line (wavy or zigzag) on a drawing indicates:

Answer: That a portion of the object has been omitted to save space

Break lines indicate that part of the object is not shown, allowing long or repetitive features to be drawn at a larger scale without showing the entire length.

In a mechanical assembly drawing, a balloon callout with a number inside refers to:

Answer: The item number corresponding to the parts list or bill of materials

Balloon callouts on assembly drawings identify parts by their item number, which links to the bill of materials for part numbers, descriptions, and quantities.

What does a 'concentricity' GD&T control verify?

Answer: That the median points of a cylindrical feature share the same axis as the datum axis

Concentricity controls the location of the median points of a cylindrical or spherical feature relative to a datum axis.

On an electrical one-line diagram for industrial power distribution, a circle with an X inside typically represents:

Answer: A motor or load

In one-line (single-line) diagrams, a circle with an X inside commonly represents a motor or electrical load connected to the distribution system.