It is standard practice to use dashes to represent any line of an object that is hidden from view. Figure 5: Use of dashed lines to represent edges hidden in views of a complicated object.

Figure 5: Use of dashed lines to represent edges hidden in views of a complicated object.

Hidden lines are used to show surfaces that are not directly visible. All surfaces must be shown in all views. If an edge or surface is blocked from view by another feature, it is drawn using a hidden line.

Phantom lines indicate the alternate position of parts of the object or the relative position of a missing part. They are composed of one long and two short evenly spaced dashes.

Answer. Answer: Object lines and hidden lines.

Phantom lines are used to indicate imaginary features such as alternate positions of moving parts and adjacent positions of related parts. The line type is long dash – short dash – short dash and the line weight is usually thin (0.3 mm).

Hidden details are shown by a series of dashes making up a broken line. It is normal practice that you place a dash at the beginning of the hidden line and another at the end where it meets an intersecting line.

Three types of lines

• Visible or Object Lines. Dark thick lines that show the outside edges of an object.
• Construction Lines. Light lines that are drawn to help place other lines on a drawing.
• Hidden Lines. Dashed lines that show parts of an object that cannot be seen from the current viewing angle.

There are four methods: parallel, running, chain, and combined dimensioning. Some methods of dimensioning a drawing can create an accumulating error.

Construction line – Very light line used to “block in” an object. These lines are made so light that little or no erasing is needed. They serve as base for darkening in the permanent line.

The heaviest line weight indicates the ground line cut. The next heaviest line weight “profiles the planes closest to the plane of projection” (Ching & Juroszek, 1998, p. 152). Medium line weight indicates distance from picture plane, progressively getting lighter to describe objects further from the picture plane.

A leader line is a line that establishes a connection between a graphical representation of an item and some text. A leader points to a bit of our drawing and says: A leader line also has a terminator and some text. A leader line may have a reference line under the text.

The dimension line is a thin line, broken in the middle to allow the placement of the dimension value, with arrowheads at each end (see diagram below).

Three principles of dimensioning must be followed:

• Do not leave any size, shape, or material in doubt.
• To avoid confusion and the possibility of error, no dimension should be repeated twice on any sketch or drawing.
• Dimensions and notations must be placed on the sketch where they can be clearly and easily read.

Which is the best choice for describing orthographic projections? They include top, bottom, back, and all side views of an object.

Short break lines are thick, wavy solid lines that are drawn freehand. When either of these break lines is used to shorten an object, you can assume that the section removed from the part is identical to the portions shown on either side of the break.

There are 5 main types of lines in art: vertical lines, horizontal lines, diagonal lines, zigzag lines, and curved lines. Other types of lines are simply variations of the five main ones.

Explanation: Out lines, dotted lines and cutting plane-lines are drawn using 2mm thickness lines. Whereas centre lines, section lines, dimension lines, extension lines, construction lines, leader lines, short break lines and long-break lines are drawn using 1mm thickness lines.

LONG BREAK LINES: Long break lines are ruled lines with freehand zigzags that reduce the size of the drawing required to delineate an object and reduce detail.

: a line perpendicular to a surface or to another line considered as a base: such as. a : a line perpendicular to the horizon.

AutoCAD Tutorial: Breakline AutoCAD

1. Type BREAKLINE and press on the ENTER key on your keyboard.
2. Specify the starting point of the Break line.
3. Specify the ending point of the Beak line.
4. Specify the location of the break symbol.

EXTENSION LINE

Typically, True Dimensions are accurate model dimensions. If you create a model and measure the length of an edge within the part or assembly and find an edge to be a certain length, the True Dimension will display that exact length as it is in the model.

Because the views are only two dimensional, more than one view is needed to completely describe the object. Usually two or three views is enough (Front, Top and Side), but often more are required.

Dimension lines and extension lines should not cross, if avoidable. However, extension lines may cross each other. 23. When extension lines cross other extension lines or visible object lines, no break in either line should be made.

Dimensioning to hidden lines should be avoided wherever possible. Use auxiliary cross sectional views instead. Longer dimensions should be placed outside all intermediate dimensions so that dimension lines will not cross extension lines.

Leaders should make a large angle (30° to 60°) with the line they touch. Leaders should never be horizontal or vertical. 28. Leader lines should never cross one another, nor should they be parallel or nearly parallel to nearby dimensions, extension, or cross-hatching lines.

An outline or a centre line should be used as a dimension line. Explanation: An outline or a centre line should never be used as a dimension line.