Short Answer
A sectional view in an engineering drawing is a representation of an object that shows its internal features by cutting through a specific plane. It is used when hidden details are not clearly visible in standard orthographic views. Sectional views help engineers understand the internal structure, holes, slots, and cavities of a component.
The purpose of a sectional view is to improve clarity, accuracy, and interpretation of a technical drawing. By removing unnecessary hidden lines and displaying internal details directly, sectional views make manufacturing, inspection, and assembly processes easier and more precise.
Detailed Explanation
Sectional View in an Engineering Drawing
A sectional view is created by cutting an object along a selected plane to reveal its internal features. The cut portion is represented using hatching or cross-hatching lines, which indicate the material of the object. These views are essential in mechanical, civil, and architectural drawings for better visualization.
- Types of Sectional Views
- Full Section: The object is cut entirely along the section plane.
- Half Section: One half of the object is cut, while the other half remains as a standard view.
- Offset Section: The section plane is bent to pass through multiple features in a single view.
- Broken-Out Section: Only a small part of the object is cut to expose internal details.
- How Sectional Views Are Created
- A cutting plane line is drawn to indicate where the object is sectioned.
- The sectioned area is hatched using parallel lines.
- The remaining uncut part of the object is shown normally.
- Features such as holes, ribs, and threads are represented according to standard conventions.
Importance of Sectional Views in Engineering Drawing
- Reveals Internal Features Clearly
- Sectional views eliminate the need for hidden lines, making the drawing easier to read.
- Improves Manufacturing Accuracy
- Provides detailed information for machining, fabrication, and assembly.
- Enhances Design Communication
- Helps engineers, machinists, and designers understand complex internal geometries.
- Standardizes Technical Drawings
- Sectional views follow ISO, ANSI, and BIS standards for universal interpretation.
- Reduces Errors in Interpretation
- Avoids misinterpretation caused by overlapping hidden lines in regular views.
Conclusion
A sectional view in an engineering drawing is a technique used to show internal details by cutting through a specific plane. It improves clarity, accuracy, and readability, making it easier for engineers and manufacturers to understand the design. Sectional views eliminate hidden lines and provide a better representation of complex components, ensuring precise manufacturing and assembly.