Steps to follow while using the feeler gauge: 1、Unfolding of the Blades – Before using the feeler gauge, you need 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 – You 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 you 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. (It's necessary to correctly implement the tool whenever it is used to getaccurate results.)