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Half section Half sections are useful when drawing a sym-metrical object. Both the inside and the out-side can be shown in one view. Use a centerline where the exterior and half-sectional views meet because the object is not actually cut. In the top view, show the complete object because no part is actually removed. If the direction of viewing is
A half section view means that you are only removing a quarter of an object. This type of view is ordinarily used when the object is symmetrical or if you only need to show a portion of a complex assembly.
- Cutting Plane. A surface cut by the saw in the drawing above is a cutting plane. Actually, it is an imaginary cutting plane taken through the object, since the object is imagined as being cut through at a desired location.
- Cutting Plane Line. A cutting plane is represented on a drawing by a cutting plane line. This is a heavy long-short-short-long kind of line terminated with arrows.
- Section Lining. The lines in the figure above, which look like saw marks, are called section lining. They are found on most sectional views, and indicate the surface which has been exposed by the cutting plane.
- Full Sections. When a cutting plane line passes entirely through an object, the resulting section is called a full section Fig. 7 illustrates a full section.
- General Principles
- Section Lines and Symbols
- Cutting Planes
- Main Principles of Placement of Sectional Views
A sectional view represents the part of an object remaining after a portion is assumed to have been cut and removed.The exposed cut surface is then indicated by section lines.Hidden features behind the cutting plane are omitted, unless required for dimensioning or for definition of the part.Section lines, or hatching, that represent the cut surface usually consist of thin parallel lines, as shown below, drawn at an angle of approximately 45° to the principal edges or axes of the part. For most purposes, the general use symbol of cast iron is used. When it is desired to indicate differences in materials, for example on assembly drawing...
Cutting plane lines which show where the cutting plane passes through the object, represent the edge viewof the cutting plane and are drawn in the view(s) adjacent to the section view. Here the cutting plane is drawn as an edge in the top view, which is adjacent to the sectioned front view. This is a frontal cutting plane. Lines of sight should alw...
Whenever practicable, and except for revolved sections, you should project sectional views perpendicular to the cutting plane and place it in the normal position for third angle projection.You should never show the views in first angle projected position on a third angle projection drawing.When the preferred placement is not practical you may remove the sectional view to some other convenient position on the drawing, but it must be clearly identified, usually by two capital letters,...Normally, you should not change orientation of the view, but if this becomes necessary, you must state the number of degrees through which it is revolved.- Section Lining. The lines in the figure above, which look like saw marks, are called section lining. They are found on most sectional views, and indicate the surface which has been exposed by the cutting plane.
- Full Sections. When a cutting plane line passes entirely through an object, the resulting section is called a full section Fig. 7 illustrates a full section.
- Half Sections. If the cutting plane is passed halfway through an object, and one-quarter of the object is removed, the resulting section is a half section.
- Broken Out Sections. In many cases only a small part of a view needs to be sectioned in order to show some internal detail. In the figure below, the broken out section is removed by a freehand break line.
External features of the part are drawn on the unsectioned half of the view. A center line, not an object line, is used to separate the sectioned half from the unsectioned half of the view. Half section views are most often used on parts that are symmetrical, such as cylinders.
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How to draw a symmetrical object with half sections?
How do you draw a symmetrical object?
What is a half section view?
How are half sections created?
What is an example of a half section?
Why are hidden lines not shown on a half section?
A Half Sectional View slices half of the object to reveal interior on one side and external features on the other. It's ideal for symmetrical objects. An Offset Sectional View displays unaligned internal features by using a staggered cutting plane, showing a 'zigzag' cut effect.
