Chapter 4: Knowledge Check

Check Your Knowledge: Chapter 4

Quiz yourself using the following chapter review questions to check how well you can recall the material.

Review Questions

1. True or false:  Machinists perform measurements so often that their eyes become accustomed to differentiating small sizes.
2. What is the term used by machinists to describe being exact or accurate?
   1. Resolution
   2. Decimal
   3. Accuracy
   4. Precision
3. True or false: When measuring dimensions in the ten thousandths (.0001”), the heat from the environment can influence the measurement.
4. How would a machinist speak a .4” measurement on a micrometer?
   1. Four tenths
   2. Forty thou
   3. Four hundred thou
   4. Four
5. True or false:  A slide caliper is the most common measuring tool because it measures the outside dimensions of a part.
6. Use the correct term to complete the sentence. To clean the OD jaws on a slide caliper, lightly close the jaws against a clean piece of __________ , then pull it out, cleaning contaminants from the faces.
7. True or false:  On digital measuring equipment, the origin and the INC (incremental) zero are the same thing.
8. Where will you most commonly find a height gage? Select all that apply.
   1. Surface plate
   2. Mill
   3. Lathe
   4. Drawer
9. Use the correct term to complete the sentence. To measure a bore, a snap gage is set with the anvils extended to a diameter __________ than the bore.
10. True or false:  A bore gage is a direct read gage, displaying the exact size of a bore.
11. True or false:  A .500” pin gage will measure exactly .500” on a micrometer.
12. Use the correct term to complete the sentence. Gage blocks are precision-ground steel tools that can be used individually or __________ to measure exact dimensions.
13. Why does a dial indicator have two dials on the face?
    1. Depth
    2. One to indicate the .1” of travel and the other .001” of travel.
    3. Diameter
    4. Inches
14. True or false:  Test indicators have a much smaller travel than drop type indicators, usually around .030”.
15. Use the correct term to complete the sentence. There is no industry standard for mounting test indicators. However, the __________ feature allows for test equipment to be mounted with very little interference from the connected equipment.

Answer Key

1. True – Just like the secret service agent, a machinist’s eye becomes trained to measure through consistent measurements.
2. Precision – Correct, precision is used often to describe the practice of making parts which reflect the engineers design
3. True – This is why micrometers have plastic insulation on them. To shield them from your body heat when handling.
4. Four hundred thou – Correct, machinists naturally add trailing zeros when speaking measurements (.400”)
5. False – The versatility of the slide caliper to measure OD, ID, depth and step are the reason the slide caliper is favored over other tools.
6. Paper – Correct.  A clean piece of paper such as a Post-it note of blue print can be used to clean the faces of the OD jaws on a caliper
7. False – Correct, the origin is set after a battery change and is the absolute zero of the tool. The INC (incremental( zero is used by the operator to measure the difference between two measurements.
8. Surface plate – Correct, a height gage will use the surface plate as a datum when measuring dimensions
9. larger – Correct, with the jaws set larger than the bore, sweeping the gage will collapse the jaws to the actual bore diameter.
10. False – When measuring a bore with a bore gage, the dial will indicate the difference between the standard used to set zero on the gage and the actual bore measurement.
11. False – Correct, the pin gage is ground undersized .0002” to allow it to fit in .500” features.
12. Combined – Correct, gage blocks can be very accurate when rung together. They are precision ground to eliminate any stack tolerance between them when assembled.
13. many times the large (.001”) dial rotated a complete rotation and the large dial will indicate the .001” of plunger travel.
14. True – Correct, a test indicator is very useful when measuring small variations.
15. Dovetail – Correct, the dovetail is used often in machining. It provides location and clamping due to the slanted faces of the feature.