A feeler gauge is one of the measuring and layout tools used for measuring the clearance between two parts. It consists of several small lengths of steel of different thicknesses with measurements marked on each piece. This tool consists of various folding leaves of metal, all connected at one centre point. They are not used for tightening the fittings.The most common application of this type of gauge is in motor vehicle repair and maintenance, and specific purposes like checking valve clearance or piston ring gaps. The raw material used for making this gauges is high-grade steel that is tempered for hard wear, durability and size of the blades.
Steps to follow while using the feeler gauge:
1. Unfolding of the Blades – Before using the feeler gauge, the user needs to remove and unfold the blades from the case.
2. Selection of leaf – Always try to select the leaf that is approximately the same width as that of the gap that you wish to measure.
3. Close back the other leaves – The system of the tool is such that the individual tool leaf can be used. To avoid bending of the other non-operated leaves, they must be folded away while measuring the gap.
4. Proper holding of the gauge – The user should hold the gauge in the same manner as you hold the pen knife or multi-tool between your thumb and forefinger. You can measure the gap by adding more than one leaf at a time for extra accuracy. A small leaf of 0.05 mm can be added along with the large leaf.
5. Be tender – Be aware of the force implied on the blades as if the blades are of thinner thickness, then they might bend when pushed into a gap.
6. Feel for a frictional resistance – There is a need for a certain type of frictional resistance while sliding the blade through the gap. It is never recommended to force the feeler gauge into the gap. It might damage the blade of the gauge while measuring the item. It might sometimes happen that the gauge might be stuck in the gap that you are trying to measure. Thus, you can always initiate a slightly thinner gauge blade. In case the gap is larger than the blade, and there is no resistance to a thicker gauge, then the user can add additional blades until the resistance feel is correct. There is a need for multiple measurements to confirm the exact size of the gap.
7. Testing of gauge for measurement – When you achieve the proper friction at that time, you will get the correct gap measurement.Thus, take-home points from this article are that it is necessary to correctly implement the tool whenever it is used to get accurate results. For that, the user should know how to use the feeler gauge in the right way.