Selecting a Feeler Gage on Amazon.com
A feeler gauge, or feeler gage, is a type of thickness gauge that has a strip or blade of a specific thickness for measuring gaps or clearance between parts in automotive, machining, and manufacturing applications. Feeler gauges are available in inch or metric sizes. They are sold singly, in coils known as feeler stock, or in an assortment of different-sized blades to take a range of measurements. Feeler stock is often used for shimming and is sometimes housed in a retractable dispenser. A feeler gauge may be straight, tapered, or offset, and usually has a rounded edge. It is most often made of a metal such as steel or stainless steel. When measuring between magnetic parts, a brass or plastic feeler gauge may be selected. A plastic feeler gauge is also nonconductive, nonsparking, and nonmarring.
Whereas a feeler gauge measures spaces between parts, other thickness gauges measure the thickness of materials or surface coatings. A dial or digital thickness gauge has a spring-loaded mechanism that quickly positions the anvil to measure paper, plastic, rubber, leather, textiles, sheet metal, and other thin materials. Some models have an anvil designed for measuring the wall thickness of tubing. For nondestructive testing of installed materials such as piping and tubing, an ultrasonic thickness gauge may be selected. It sends ultrasonic waves through a material to determine its thickness, and can test materials such as steel, cast iron, aluminum, red copper, zinc, quartz glass, polyethylene, and PVC (polyvinyl chloride).
A coating or paint thickness gauge measures the thickness of paint, anodizing, galvanizing, and other surface coatings. Some of these gauges test ultrasonically, while others use magnetic induction to test ferrous materials or eddy current measurement to test non-ferrous materials. They generally measure in mils and are available with different measuring ranges. Most are handheld digital devices that may offer features such as minimum and maximum readings, high-low indicators, on-board memory for storing readings, and digital output for transferring readings to a computer. For accessing hard-to-reach areas, a gauge with a probe may be selected.