A blade feeler gauge is probably the most common type of gap gauge you will encounter when shopping for these tools online. They usually feature a range of graded flattened metal shims or leaves which are designed to fold in or out of a central case or sheath. The number of blades or leaves – Different feeler gauge sets will feature different numbers of blades. On the low side, 10 or less, with 13, 15, 25, 26, 31 being more common blade counts, all the way up to over 100.

Buy a set of precision gauges for measuring difficult to reach gaps in some parts. These feeler gauges come in a variety of sizes, from 0.0015 to 0.035 inches.There are models in different formats (for example, with single blades or in the form of a roll) and also the radius calibrators used to measure concave or convex rays. To alter the spark gap, twist a little, the ground electrodes away or toward the center electrodes. Step 3: Now Use Any Other Tool if Required The most common type of feeler gauge, called a straight leaf or straight blade gauge, consists of straight blades of uniform width constructed of high carbon steel sold in a set to cover specific dimensional values. However, there are variations on this standard that serve specific purposes. However, for many standard engineering and mechanical applications, tempered or stainless steel is often the preferred material. Brass can also be a good option if you need something durable, but somewhat softer and less likely to scratch than steel.

This CTA gap adjustment tool only weighs 1.44 ounces and will offer over 30 accurate gaping measurements before you need to readjust it. It also includes one electrode-adjusting tool. The unit is designed to adjust the plug without pressuring the center electrode. The tool can be used at home and in a professional garage. Blade length – Standard blade lengths are typically around 3-5 inches, but long blades might be 12 inches and shorter blades around ¾ - 1 inch. Are you confused about how this instrument works? See the step by step below, where we use as an example the measurement of a spark plug: Now that you know that there are different models of gap gauge, you need to evaluate which is the most suitable for the equipment you want to measure. There are several ways to measure the pitch of a thread, although in the case of pipe threads, the most convenient is by using a thread gauge. 05. Identify the Thread

Specifications for Feeler Gauges

Within the blade variety of gauge, some variations include changes to the blade length (long blade and short blade feeler gauges) as well as bent blade (also called offset) gauge sets. The bent blade gauge set can provide for easier use in space-constrained applications and for use in areas with restricted movement and access to the gap being measured. There is also a tapered blade type of gauge set, wherein the width of the blade becomes progressively narrower towards the blade tip, which again, can prove valuable when there are space limitations involved in the work area. Correctly gap your new spark plug. Your original spark plug may come pre-gapped by the manufacturer. These plugs have a designated ignition gap, heat range, and torque that works for your engine. A new spark plug may not have the same gap size, and if you install it with a smaller or larger gap, you may notice a significant decline in your engine’s performance. This measurement will give us the number of threads per inch on UNC, UNF, NPT, BSPP, and BSPT threads, and the distance in millimeters between two consecutive ridges on metric threads.

For this reason, it is essential to ensure that we properly identify the threads with which we are dealing, and for this purpose, it is convenient to follow a simple methodology to read a feeler gauge. 01. Determine if the Thread is Male or Female For working with very delicate or easily scratched materials, you may be better off with a plastic feeler gauge than a metal one. The same is also true if you are working in environments where a metal version might corrode, conduct electricity, or cause sparking. A feeler gauge is a tool that is used to measure gap width. Here in the following guide, we are going to learn how to read a feeler gauge. Gauges establish a distance between two points. The device consists of multiple sheets or wires sized to exact dimensions marked on the surface of each blade or at the base of each cable. The fan-shaped model is often used to manufacture and maintain automotive aviation equipment. However, as explained above, it can also be used in the measurement of car spark plugs. How to Gap Spark Plugs with Feeler Gauge? img source: apex-pitbikes.de In a similar way to the previous case, we use the gauge to measure the external diameter of a male thread or the internal diameter of a female thread, taking into account the following detail:It is mainly used when measuring the gap between the segment ring and the piston of an endothermic combustion engine or the gap between two gears. Measurements that involve the use of a feeler gauge are generally very small and are always very accurate. Auto repair technicians need accurate gap measurements when working with spark plugs, distributors, or valves. Mechanical assemblies such as machines are built up from a series of mating parts. The fit of those parts is often designed to be within a specified tolerance that assures reliable operation for the machine – for example, the fit of a piston into the cylinder of an engine. If there is too tight a fit or clearance between the piston and cylinder, the engine may suffer from excessive wear and friction, shortening the life of the unit and resulting in maintenance costs and downtime. If the gap or clearance is too wide, combustion gases may escape during compression, reducing the engine performance. To make certain that gaps and clearances are within specified limits, engineers, mechanics, and machine operators rely on the use of measuring devices such as a feeler gauge. This article covers what feeler gauges are, the various types that exist, the gauge sizes, and provides some examples of typical uses for these instruments. All feeler gauges are somewhat thin. This is because the point of them is to fit into and measure gaps that are far too narrow for most other common measuring tools, such as tape measures.

The spark plug comes into play in charge of supplying the ignition sparks to ignite the fuel in the combustion chambers. The CTA Tools Spark Plug Gap gauge is made up of a strong and durable all-steel construction built to resist corrosion. It’s a circular gauge with easy-to-read, laser-etched sizes on its body in sizes ranging from 0.025 to 0.060 inches with 0.005 increments. Nine wire rings on the gauge's outer edges help you to accurately measure, increase, and decrease the gap size.As well as, when repairing or replacing spark plugs, a technical service center measures or establishes the distance between two electrodes by using a feeler gauge. The sizes range from 0.02 to 0.1 inches with 0.01 increments, and they are easy to read. The gapper is also designed with a key ring hole or a spark gap opener with a 7/16 inch diameter. The hole helps you accurately resize spark plugs with an electrode tool included. The tool can measure the clearance of any spark plug model. The CTA Tools Spark Plug Gapper has a heavy-duty construction built for strength and durability. It’s made up of a die-casted metal to harden the steel and increase the accuracy of the unit. It can be used for measuring and readjusting the spark plug gap. The gauge is calibrated in the imperial system, and the size markings are laser etched on the rugged steel construction.