Mechanical Engineering - Engineering Materials - Discussion

The correct answer is: nickel-chrome steel.

Nickel-chrome steel, also known as 18/8 stainless steel, is a popular choice for making precision measuring instruments due to its unique properties:

1. High corrosion resistance.
2. Low thermal expansion.
3. High dimensional stability.
4. Good mechanical properties (strength, toughness).
5. Resistance to magnetic interference.

Nickel-chrome steel contains approximately 18% chromium and 8% nickel, which provides excellent corrosion resistance and stability. This makes it an ideal material for precision instruments, such as:

1. Gauges.
2. Calipers.
3. Micrometers.
4. Dial indicators.
5. Precision scales.

The other options are not correct because:

- Nickel steel is not as corrosion-resistant as nickel-chrome steel.
- High-speed steel is designed for high-temperature applications and is not typically used for precision measuring instruments.
- Chrome-vanadium steel is a high-strength steel alloy, but it is not as corrosion-resistant as nickel-chrome steel and may not provide the same level of dimensional stability.

The specific composition and properties of steel alloys can vary depending on the application and manufacturer.

It has low coefficient of thermal expansion.

Yes, it is due to low thermal expansion.

It has a high thermal conductivity.

Usually invar or nickel steel.