All About Feeler Gauges - Definition, Sizes, and Uses

What is Feeler Gauge?

A feeler gauge is a precision measuring tool used to measure the gap or clearance between two surfaces. It typically consists of a set of flat, thin, and flexible metal strips or blades of varying thicknesses, with each strip marked or labeled with its thickness. The strips are inserted between the two surfaces, and the one that fits snugly without being too tight or too loose indicates the gap or clearance between them. Feeler gauges are commonly used in automotive, aviation, and mechanical applications for tasks such as setting valve clearances, adjusting spark plug gaps, and measuring bearing clearances.

Defferent types of feeler guage 

Types of feeler gauge:

There are different types of feeler gauges available for different applications, some of which include:

1. Straight Blade Feeler Gauge.

2. Tapered Blade Feeler Gauge

3. Radius Gauge.

4. Wire Gauge.

5. Offset Feeler Gauge.

6. Dual-Reading Feeler Gauge.

7. Combination Feeler Gauge.

8. Go/No-Go Feeler Gauges.

1. Straight Blade Feeler Gauge - This type of feeler gauge consists of straight blades of varying thickness. It is commonly used for measuring the clearance between two flat surfaces.

A straight blade feeler gauge typically has a set of blades, each with a specific thickness measurement marked on it. The number of blades in a straight blade feeler gauge can vary depending on the manufacturer and the specific set, but a common range is between 12 and 32 blades. However, some sets may have more or fewer blades depending on the required measurement range and precision.

2. Tapered Blade Feeler Gauge - This type of feeler gauge has blades that are tapered towards one end. It is commonly used for measuring the clearance between two non-parallel surfaces.

The number of blades in a tapered blade feeler gauge can vary depending on the specific model and manufacturer. However, typically, tapered blade feeler gauges come in sets of multiple blades ranging from around 10 to 30 blades.

3. Radius Gauge - This type of feeler gauge has a set of blades with different radii, which are used for measuring the curvature of a surface.

Typically, a radius gauge set can have anywhere from 16 to 32 blades or more. The blades are usually labeled with their corresponding radius measurement and may range from very small radii of a few millimeters to larger radii of several inches.

4. Wire Gauge - This type of feeler gauge consists of a set of wires of varying thickness. It is commonly used for measuring the gap between two parts, such as spark plug gaps.

5. Offset Feeler Gauge - This type of feeler gauge has a bent or angled blade, which is useful for measuring clearances in hard-to-reach areas.

6. Dual-Reading Feeler Gauge - This type of feeler gauge has two scales on each blade, allowing for both metric and imperial measurements.

7. Combination Feeler Gauge - This type of feeler gauge includes a set of blades with varying thicknesses and shapes, making it useful for a wide range of applications.

8. Go/No-Go Feeler Gauges: These gauges have two blades, one for the go measurement and one for the no-go measurement, which allows the user to check if a particular gap or space is within tolerance.

Feeler gauges in various sizes:

Feeler gauges come in various sizes, typically ranging from 0.04mm to 1.00mm in thickness. The specific sizes included in a feeler gauge set can vary depending on the manufacturer and the intended use of the gauges.

Here are some of the common sizes you may find in a feeler gauge set:

0.04mm

0.05mm

0.06mm

0.07mm

0.08mm

0.09mm

0.10mm

0.15mm

0.20mm

0.25mm

0.30mm

0.40mm

0.50mm

0.75mm

1.00mm

Again, the specific sizes included can vary depending on the manufacturer, so be sure to check the product description or packaging before purchasing a set.

Application of feeler gauge:

A feeler gauge is a precision measuring tool used to measure the clearance or gap between two parallel surfaces. It consists of a set of thin, flat metal blades of various thicknesses, each marked with the measurement it represents. Here are some common applications of feeler gauges:

1. Engine Valve Adjustment: Feeler gauges are commonly used to measure the gap between the valve stem and rocker arm or camshaft lobe. This gap is important for ensuring proper valve operation and engine performance.

2. Spark Plug Gap Adjustment: Feeler gauges are used to measure the gap between the center and ground electrodes of a spark plug. The correct gap ensures proper ignition and engine performance.

3. Brake Pad Clearance: Feeler gauges are used to measure the clearance between the brake pad and rotor. The correct clearance ensures proper brake performance and prevents brake drag.

4. Ignition Timing Adjustment: Feeler gauges can be used to measure the gap between the distributor points or the distance between the reluctor and pickup coil in electronic ignition systems. This gap is critical for setting the ignition timing correctly.

5. Bearing Clearance: Feeler gauges are used to measure the clearance between the crankshaft and main bearings or connecting rod bearings. The correct clearance ensures proper lubrication and prevents excessive wear.

Overall, feeler gauges are a versatile tool that can be used in many different applications where precise measurements are required.

Specifications of feeler gauge:

Here are some common specifications of a feeler gauge:

1. Material: Feeler gauges are typically made of high-quality steel, such as stainless steel or hardened and tempered steel.

2. Blade lengths: Feeler gauge blades come in various lengths, typically ranging from 3 to 12 inches.

3. Blade thicknesses: The thickness of the individual blades ranges from 0.0015 to 0.035 inches (0.04 to 0.88 mm), with each blade being marked with its thickness.

4. Number of blades: A standard set of feeler gauges includes multiple blades, typically ranging from 12 to 32.

5. Measurement units: Feeler gauges are usually marked in both imperial (inches) and metric (millimeters) units.

6. Handle: Some feeler gauges come with a handle or holder to make it easier to use and to keep the blades organized.

7. Accuracy: Feeler gauges are typically accurate to within a few thousandths of an inch (or hundredths of a millimeter) and are commonly used to measure small clearances or gaps.

8. Uses: Feeler gauges are commonly used in a variety of mechanical applications, including checking valve clearances, measuring spark plug gaps, and setting the gap on ignition points.

Usage of Feeler gauge:

Here are some common uses of a feeler gauge:

1.Measuring gaps: A feeler gauge is often used to measure the gap between two surfaces, such as the gap between two engine parts. This measurement is critical in ensuring proper functioning and preventing damage.

2. Checking valve clearances: In engines with overhead valves, a feeler gauge is used to check the clearance between the valve stem and the rocker arm or camshaft.

3. Setting spark plug gaps: A feeler gauge is used to set the gap between the center and ground electrodes of a spark plug to ensure proper combustion.

4. Adjusting carburetors: A feeler gauge is used to set the clearance between the carburetor's throttle valve and its bore to achieve the correct air-fuel mixture.

To use a feeler gauge, you typically slide the blade or blades of the appropriate thickness between the two surfaces being measured until you feel resistance.