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7.1 What instrument will be used to measure the diameter of the indentation on the test material when using a Brinell hardness tester? 7.2 State TWO methods to determine the Brinell hardness number - NSC Mechanical Technology Fitting and Machining - Question 7 - 2023 - Paper 1
Question 7
7.1 What instrument will be used to measure the diameter of the indentation on the test material when using a Brinell hardness tester? 7.2 State TWO methods to dete... show full transcript
Worked Solution & Example Answer:7.1 What instrument will be used to measure the diameter of the indentation on the test material when using a Brinell hardness tester? 7.2 State TWO methods to determine the Brinell hardness number - NSC Mechanical Technology Fitting and Machining - Question 7 - 2023 - Paper 1
Step 1
What instrument will be used to measure the diameter of the indentation on the test material when using a Brinell hardness tester?
Answer
The instrument that will be used to measure the diameter of the indentation is a microscope. It provides the necessary magnification to accurately assess the size of the indentation.
Step 2
Step 3
Step 4
Describe the working principle of a tensile tester.
Answer
The tensile tester operates on the principle that it subjects a piece of material to an increasing axial load while measuring the corresponding elongation of the material. It is a destructive testing method used to evaluate the material properties such as tensile strength and ductility.
Step 5
What is the difference between a depth micrometer and a screw-thread micrometer with regard to the scales on the barrels of the instruments?
Answer
The scale on the depth micrometer's barrel reads in the opposite direction compared to the screw-thread micrometer. This means that when measuring with a depth micrometer, the measurements display a decreasing value while the screw-thread micrometer displays an increasing value.
Step 6
State THREE ways how to assess the hardness of metals.
Answer
- Resistance to penetration / hardness tests: This method assesses how easily a hard object penetrates the surface of a metal sample.
- Sound test: This involves striking the metal and evaluating the sound it produces to determine hardness characteristics.
- Elastic hardness / bending test: In this method, the amount of deflection in response to an applied force is measured.
Step 7
Mr Patterson is using a depth micrometer to measure a hole. The measurement reading on the micrometer is 5,94 mm and a 50–75 mm interchangeable rod is used. What will be the CORRECT depth measurement of the hole?
Answer
The correct depth measurement of the hole can be calculated using the formula:
Correct depth measurement = Micrometer reading + Length of interchangeable rod
Therefore, the correct depth measurement will be: