Which of the following is NOT a way of visually representing bolts and screws on a drawing?

The reason "rough" is not considered a standard method for visually representing bolts and screws on a drawing stems from the definition and purpose of common drawing representations in engineering and technical graphics.

Typically, a schematic representation is used to convey functional relationships and connections between components in a logical and straightforward manner, providing clarity to the overall design. Pictorial representations give a three-dimensional perspective, allowing viewers to visualize the component's physical characteristics, while simplified views focus on providing essential details without unnecessary complexity, making the drawings easier to interpret.

In contrast, a "rough" representation does not conform to established standards of accuracy and clarity; it implies a lack of detail and precision that is generally not useful in technical drawings. This distinction is key in ensuring that the drawings effectively communicate the intended specifications and assembly instructions for bolts and screws.