What are the three types of Scribers mentioned?
- Pocket Scriber
- Engineer’s scribe
- pocket scriber with Carbide Point
These scribers are used for precise marking in engineering.
What determines the size of dividers?
Length of legs
Dividers range from 6 to 12 inches.
What are the two types of dividers?
- Firm joint
- Spring type
These types affect the functionality and ease of use.
What are trammels used for?
To scribe arcs, circles, and transfer measurements beyond the range of dividers
Trammels are essential for larger measurements.
What does each graduation on the main scale of a protractor represent?
1°
The vernier scale on a universal bevel protractor has two scales for enhanced accuracy.
Name the transfer measuring instruments mentioned.
- Calipers
- Telescoping gauges
- Small hole gauges
These instruments are used for precise measurements.
What are spring calipers used for?
Very accurate work
They feature a solid or quick adjustment nut for fast setting.
What is the most common type of material used for surface plates?
Granite
Surface plates come in various shapes: octagonal, round, hexagonal, and square.
What are the three grades of surface plates?
- AA - laboratory grade
- A - inspection grade
- B - tool room grade
These grades indicate the quality and precision of the surface plates.
List the six precautions when using a surface plate.
- Don’t hammer or punch on it
- Keep covered when not in use
- Keep clean
- Protect by using parallels
- Place work carefully
- Remove burrs and protrusions
These precautions help maintain the integrity of the surface plate.
What should you never sharpen on a knife edge scriber?
The bottom
Always sharpen the top edge for optimal performance.
What is the purpose of a punch/witness mark around a laid out hole?
Acts as a visual aid when drilling
It helps to show if the drill is off.
What is another name for a universal bevel protractor?
Vernier protractor
It uses a vernier scale to enhance reading accuracy.
What angles can a bevel protractor layout?
0°-180°
This tool is versatile for various angle measurements.
What is the purpose of a center head?
To locate the center on the end of round, square, and octagonal shafts
It is useful for ensuring precision in machining.
