Engineering Metrology Questions and Answers – Feeler Gauges

1. A Filler gauge is also called as

  1. Thinness Gauge
  2. Thickness Gauge
  3. Diameter Gauge
  4. Radius Gauge

Answer.2. Thickness gauge

Explanation:-

Feeler gauges, also known as thickness gauges consist of several thin hardened strips, blades or leaves. The blades vary in thickness. The blades are held together at one end with a screw, so that any blade may be selected for use.

feeler gauge

 

2. The application of filler gauge is/are

  1. Measuring and testing clearance
  2. To measure the gap width
  3. Adjusting spark Plug
  4. All of the above

Answer.4. All of the above

Explanation:-

Feeler gauges are used for the following:

  1. Measuring and testing clearances such as tool clearance to work.
  2. For measuring the width of the gap between two parallel flat faces, e.g. in gauging of the clearance between the piston and cylinder.
  3. For adjusting spark plugs and so on.
  • Feeler gauges find application wherever there is a need to accurately establish the size of the clearance or gap between two mating machine elements or surfaces and where other measuring devices, such as calipers or a steel rule, are not able to be employed.
  • They are commonly used across a wide range of industries such as aerospace, automotive, pharmaceutical, oil & gas, and general industrial machining.
  • In automotive applications, feeler gauges can be used to set the valve clearance between the rocker arms and the valve stem and to adjust the spark plug gap.
  • In oil refinery applications, wall slot size in reactor vessels can be checked with a feeler gauge. 

 

3. What is the tensile strength of blade of feeler gauge with thickness up to 0.5 mm?

  1. 170 kgf/cm2
  2. 1.70 kgf/cm2
  3. 50 kgf/cm2
  4. 70 kgf/cm2

Answer.1. 170 kgf/cm2

Explanation

Feeler gauges generally comprise of a series of gauging blades of different grades and thicknesses from 0.03 mm to 1 mm. The blades are made of heat-treated bright polished tool steel having a tensile strength of about 170 kgf/cm2 for thickness up to 0.5 mm and about 70 kgf/cm2 for thickness up to 0.5 mm and above.

 

4. The most common type of feeler gauge is also known as

  1. Twisted blade
  2. Cross blade
  3. Straight blade
  4. Box blade

Answer.3. Straight blade

Explanation:-

The most common type of feeler gauge called a straight leaf or straight blade gauge consists of straight blades of uniform width constructed of high carbon steel sold in a set to cover specific dimensional values.

 

5. What is the most common standard length of a feeler gauge blade?

  1. 50 mm
  2. 20 mm
  3. 70 mm
  4. 100 mm

Answer.4. 100 mm

Explanation:-

  • A feeler gauge is a tool used to measure gap widths.
  • Blade length – Standard blade lengths are typically around 3-5 inches (75 – 127 mm), but long blades might be 12 inches (304.8 mm) and shorter blades around ¾ – 1 inch.
  • The most common standard length of a feeler gauge blade is 100 mm

 

6. Some of the thickness blades are bent upto the angle of

  1. 10 to 20 degree
  2. 45 to 90 degree
  3. 20 to 40 degree
  4. 1 to 45 degree

Answer.2. 45 to 90 degree

Explanation:-

Feeler gauge or thickness gages can be made with multiple blades (usually 2 to 26).

Each blade is a specific number of thousandths of an inch thick. This enables the application of one tool to the measurement of a variety of thicknesses.

Some thickness gauge blades are straight, whereas others are bent at 45 and 90 degree angles at the end.

Thickness gages can also be grouped so that there are several short and several long blades together. Before using a feeler gauge, remove any foreign matter from the blades.

 

7.  Which of the following is incorrect about the feeler gauge?

  1. Feeler gauge can be used to check spark plug gaps
  2. A Feeler gauge has a number of blades of equal thickness
  3. Blades are hinged in a sheath
  4. Each thin blade is inter-leaved between two thick blades

Answer.2. A Feeler gauge has a number of blades of equal thickness

Explanation:-

Feeler gauges are used for the following:

  1. Measuring and testing clearances such as tool clearance to work.
  2. For measuring the width of the gap between two parallel flat faces, e.g. in gauging of the clearance between the piston and cylinder.
  3. For adjusting spark plugs and so on.

Feeler gauges generally comprise of a series of gauging blades of different grades and thicknesses from 0.03 mm to 1 mm. Feeler gauge can be made with multiple blades (usually 2 to 26). Each blade is a specific number of thousandths of an inch thick. This enables the application of one tool to the measurement of a variety of thicknesses. The blade are hinged in a sheath.

Feeler gauge can also be grouped so that there are several short and several long blades together. Before using a Feeler gauge, remove any foreign matter from the blades. You cannot get the correct measurement.

 

8. The blade material used in the Feeler gauge are

  1. Steel
  2. Brass
  3. Plastic
  4. All of the above

Answer.4. All of the above

Explanation:-

The blade material used in the filler gauges are either grade I and grade II type.

In Feeler gauge, carbon steel blades are commonly used, but other materials such as brass, stainless steel, and even plastic blades are available.

Brass has the advantage that it will not precipitate a spark while in use, valuable for applications where explosive atmospheres might exist. Brass is also is non-corrosive and non-magnetic, desirable properties in uses such as electronics.  Brass-made Feeler gauges are used to take measurements between components that are magnetic. If steel gauges are used, the drag caused by the magnetism would mimic the drag of a proper clearance. Brass gauges are not subject to magnetism, so they work well in that situation.

Stainless steel can resist high temperatures, and plastic is non-corrosive, non-sparking, non-marring, and non-magnetic.

Some of the gauge sets will offer blades of more than one material in the same set, such as steel and brass together.

 

9. Which of the following option is correct for given statements?

Statement 1: A feeler gauge can be used to check the clearance between cylinder and piston.

Statement 2: The working of feeler gauges is completely dependent on the sense of feel.

  1. Statement 1 is true but statement 2 is not true

  2. Statement 2 is true but statement 1 is not true

  3. Both the statements are not true

  4. Both the statements are true

Answer.4. Both the statement is true

Explanation:-

The measuring efficiency depends entirely on the sense of feel, that is why it is the caller feeler gauge. The feeler blade should neither be forced between the surfaces nor should it slide freely, rather the correct blade will give a characteristic ‘gauge fit’ type of feel. 

 

10. Which of the following option is correct for given statements?

Statement 1: Two or more non-stepped feeler gauges can be stacked together.

Statement 2: Unknown gap can’t be measured by feeler gauge

  1. Statement 1 is true but statement 2 is not true
  2. Statement 2 is true but statement 1 is not true
  3. Both the statements are not true
  4. Both the statements are true

Answer.1. Statement 1 is true but statement 2 is not true

Explanation:-

Some feeler gauges come in a bent arrangement to be more easily inserted in cramped spaces. Others come in a stepped version. For example, the end of the gauge might be 0.010″ thick, while the rest of the gauge is 0.012″ thick. This works well for adjusting valve clearance.

Two or more non-stepped feeler gauges can be stacked together to make up the desired thickness. For example, to measure a thickness of 0.029 of an inch, a 0.017 and a 0.012 feeler gauge could be used together to make up the size.

Alternatively, if you want to measure an unknown gap, you can interchange feeler gauges until you find the one or more that fits snugly into the gap and total their thickness to determine the measurement of the gap. In conjunction with a straight edge, they can be used to measure surface irregularities on a cylinder head.

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