Chapter 5: Orthographic Writing Conventions

A view representing specific parts of an object with features needing clarification.

A partial view showing half of an object, usually symmetrical.

A view focusing on specific features needing clarification.

A view created by rotating an object's features around a symmetry axis.

Align views ensure accurate representation without distortion and simplify dimensioning.

An imaginary line dividing an object into symmetrical halves.

For symmetrical objects, features are best shown in adjacent views at their true radial distance from the symmetry axis.

A symbol used to indicate a line of symmetry in a drawing.

A commonly accepted practice that slightly deviates from strict orthographic projection rules for improved readability and efficiency.

Convention practices aim to enhance drawing clarity, simplify dimensioning, reduce drafting effort, and optimize space utilization.

A convention practice where the side view is placed beside the top view, particularly when an object has a small height and a large depth.

It simplifies a side view by omitting features that cannot be seen clearly from the chosen viewing direction.

A convention practice where a view is aligned with the adjacent view to improve visibility and reduce clutter.

A convention practice where a portion of an object is enlarged to highlight details or clarify intricate features.

A convention where a line is drawn to represent an imaginary intersection, even if it's not physically present in the object.

A convention where a hole or cutout in a cylinder is represented by a visible circular shape, even when viewed from an angle.

A method of representing a 3D object using multiple 2D views to show its true shape and dimensions.

A detailed view of a specific part of the object, drawn at a larger scale than the main view.

Following standard practices for representing technical drawings, ensuring clarity and consistency.

A line added to a drawing to show the true intersection of surfaces, even if rounded corners or fillets hide it.

Positioning the view of an object so the holes appear in a clear and symmetrical way.

Arranging the object's view to show the ribs effectively, with straight edges and clear outlines.

Combining the principles of aligning both holes and ribs to create a comprehensive and clear view.

Arranging the view to show ribs, holes, and a keyway in a way that presents a complete understanding of the part.

Dimensions that define the position of features on a part, like the placement of holes. They indicate where something is located relative to other features.

Dimensions that specify the size of features on a part, like the width, depth, and thickness. They tell you how big something is.

To show an angle on a drawing, use a circular dimension line centered at the angle's vertex.

Show the arc's radius with the letter 'R' before the value, placing the dimension figure and arrowhead inside or outside the arc as needed.

A rounded edge or corner created by a small arc, usually with a consistent radius.

Use a local note to show the radius of a typical fillet. If all fillets are the same, use a note like "All fillets are Rxx."

Use this when the arc's center is off the drawing or interferes with other views. Draw the dimension line radially from the arc.

Specify the radius of a specific fillet using a local note. If all fillets are uniform, note "All fillets and rounds are Rxx."

The standard unit for length in technical drawings is millimeters (mm), and no unit symbol is required.

The standard unit for angles in technical drawings is degrees (°), and the symbol must be included.

Dimension figures are placed so they can be read from the bottom and right side of the drawing.

Dimension figures are placed so they can be read only from the bottom of the drawing.

Notes placed near the feature they describe and outside the view, always read horizontally.

The main purpose of dimensioning is to provide all the necessary size and location information to accurately manufacture an object.

Incorrectly placed dimension figures (too far away from the feature) make the drawing inaccurate and misleading.

Incorrectly placed dimension figures (too far away from the feature) make the drawing inaccurate and misleading.

To define a curve, you need the radii of its arcs and the location of their centers.

A cylinder is described by its diameter and length, and its location is referenced from its center lines, usually shown in a circular view.

Holes are dimensioned with their diameter and depth, with location referenced from center lines in a circular view.

Small holes are dimensioned with a leader line and local note indicating diameter and depth in the circular view.

A through hole goes all the way through the object. A blind hole has a specific depth.

Large holes use extension and dimension lines to show the diameter, often with a leader line and note.

A chamfer is defined by its linear distance and angle, indicated with a leader line and note.

Extension lines should not cross dimension lines, start from the nearest points, and can cross visible lines without gaps. Avoid using object, center, or dimension lines as extension lines.