How to choose a feeler gauge
|Your choice of feeler gauge will depend on how accessible the gap is that you are measuring. A few examples of when each type can be used are listed below. Please note that feeler gauge applications are likely to overlap because the tools have minimal differences.
|The choice of metric or imperial measurement is preferential. It is often easier to measure clearances using the same units that are given in a parts specification or user manual.
When to use a straight leaf feeler gauge
|You may insert a straight leaf feeler gauge under intake lobes as the clearance should be set parallel over a continued length.
The length of a straight leaf gauge is useful when setting a gap between two surfaces which remain in close contact for an extended distance.
They are commonly used for adjusting tappets, spark plugs, distributor points and fitting pistons.
When to use a tapered leaf feeler gauge
|You may use a tapered leaf feeler gauge when you need to measure tappet clearances or in other particularly awkward positions.
It may be the case that the straight leaf gauge is too wide to fit precisely between the two surfaces.
They are commonly used to measure gaps between shafts, bearings and electrical contacts.
When to use a Go NoGo feeler gauge
|Go NoGo feeler gauges are commonly used to adjust valve tappets.
Their stepped design helps to identify simply yes or no when checking if a gap fits within a specified range. (e.g. 0.016 to 0.018)
When to use feeler strips
|Feeler strips may be placed between a lathe chuck and tailstock to see if the centres are aligned. The metal strip will tilt if the centres are not true.
When to use an offset feeler gauge
|An offset gauge can be used for valve adjustment as the angle helps with access to the clearance.