A feeler gauge is a
tool
A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates bac ...
used to measure gap widths. Feeler gauges are mostly used in
engineering
Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...
to measure the clearance between two parts.
Description
They consist of a number of small lengths of steel of different thicknesses with measurements marked on each piece. They are flexible enough that, even if they are all on the same hinge, several can be stacked together to gauge intermediate values. It is common to have two sets: one for
imperial unit
The imperial system of units, imperial system or imperial units (also known as British Imperial or Exchequer Standards of 1826) is the system of units first defined in the British Weights and Measures Act 1824 and continued to be developed thr ...
s (typically measured in
thousandths of an inch), and one for
metric
Metric or metrical may refer to:
* Metric system, an internationally adopted decimal system of measurement
* An adjective indicating relation to measurement in general, or a noun describing a specific type of measurement
Mathematics
In mathema ...
(typically measured in hundredths of a
millimetre
file:EM Spectrum Properties edit.svg, 330px, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is between 1 meter to 1 millimeter.
The millimetre (American and British Eng ...
) measurements (with intervals of thousandths of an inch and hundredths of a millimetre being roughly in the same order of magnitude).
The same device with wires of specific diameter instead of flat blades is used to set the gap in
spark plugs
A spark plug (sometimes, in British English, a sparking plug, and, colloquially, a plug) is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air ...
to the correct size; this is done by increasing or decreasing the gap until the gauge of the correct size just fits inside the gap.
The lengths of steel are sometimes called ''leaves'' or ''blades'', although they have no sharp edge.
Stainless steel is a common material for feeler gauges. Some feeler gauge sets have a single blade of brass due to the historical reason that early electronic ignition systems required the air gap between the reluctor and the pickup part being set with a non-ferrous metal.
What are feeler gauges made from? - Wonkee Donkee Tools
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Types
Taper
A taper feeler gauge is a feeler gauge of tapered, as opposed to parallel, shape. The blade of the gauge is of a constant thickness, and the two types of gauge are used in a similar way.
See also
*Plastigauge Plastigauge is a measuring tool used for measuring plain bearing clearances, such as in engines. Other uses include marine drive shaft bearings, turbine housing bearings, pump and pressure system bearings, shaft end-float, flatness and clearance ...
References
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Length, distance, or range measuring devices
Metalworking measuring instruments