Universal Bevel Protractor – Parts and Functions
A Universal Bevel Protractor is a precision angular measuring instrument used to measure angles accurately. It is widely used in mechanical workshops, tool rooms, and quality control departments for angular measurement up to 5 minutes (1/12th degree).
Main Parts of Universal Bevel Protractor and Their Functions
| Part Name | Description | Function |
|---|---|---|
| 1. Base (Stock) | A flat and heavy base made of hardened steel. | Provides stability and is placed firmly on the surface or edge being measured. |
| 2. Adjustable Blade | A long, narrow, and flat blade connected to the circular scale. | Acts as a reference line; can be rotated and set at various angles. |
| 3. Dial (Circular Scale) | A circular graduated scale marked in degrees (0° to 360°). | Measures the angle between the stock and blade. |
| 4. Vernier Scale | A small scale attached to the dial. Usually reads in 5 minutes of a degree. | Increases precision by allowing accurate reading of fractional angles. |
| 5. Locking Knob/Screw (Blade Clamp) | A screw that fixes the blade in position after adjustment. | Locks the blade at the desired angle for measurement or marking. |
| 6. Magnifying Glass (optional) | Sometimes provided above the vernier for better readability. | Enhances visibility of small divisions on the scale. |
| 7. Fine Adjustment Knob | A screw used to make fine changes in the blade angle. | Allows precise alignment of the blade with the workpiece. |
| 8. Acute Angle Attachment | A detachable arm used for measuring acute or inside angles. | Helps in measuring sharp or difficult-to-reach angles. |
Diagram Description (for sketching in Word)
To create a sketch of the Universal Bevel Protractor:
- Draw a semicircular protractor dial with degree markings from 0° to 360°.
- Attach a flat base (stock) at the bottom.
- Show a movable blade extending from the center, adjustable over the dial.
- Label vernier scale, locking screw, and fine adjustment knob.
- Optionally, add an acute angle attachment to the blade.
📝 Caption: Parts of a Universal Bevel Protractor
How It Works
- Place the base (stock) firmly along the reference surface of the workpiece.
- Adjust the blade to align with the slanted or angled surface.
- Read the angle on the circular scale where the blade points.
- For precise measurement, note the vernier scale reading to get the exact angle up to 5 minutes (‘).
- Lock the blade with the clamp screw once the angle is measured or set.
Applications
- Used for checking angles in machine parts, dies, and tools.
- Ideal for marking and measuring acute, obtuse, and right angles.
- Commonly used in engineering drawing, fabrication, and inspection tasks.
Advantages
- High accuracy (up to 5 minutes)
- Can measure all types of angles
- Durable and long-lasting
- Easy to operate
Conclusion
The Universal Bevel Protractor is a highly reliable and essential tool in any workshop or engineering environment. Its parts work together to allow precise angular measurements, making it an important instrument for quality control and layout work.