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.

The specific feeler gauge sizes included in a set depend on the number of blades in the set as well as whether the feeler gauge set is an English or metric size set. A representative set of feeler gauge sizes for a decimal inch set is shown below in Table 1, and a decimal millimeter size set is shown in Table 2. These are based on a 25-blade count set – other blade combinations and sizes are available. Below, we have listed some of the most common types, materials and models of feeler gauges. Most are available either as full sets or as individual blades. Wire Type Feeler Gauges Both instruments are very useful for toolmakers, mechanics, automatic lathes operators, modelers, and professionals in related fields. How to Read a Feeler Gauge- 5 Steps Process img source: axminstertools.com The OEM Tools Blade Master has 26 calibrated blades that can measure sizes ranging from 0.0015 to 0.025 inches. You can get the exact value of the gap in either SAE or metric system (inches and millimeters). The measurements are laser etched in the middle of each blade. The blades are made of hardened tempered steel, which is long-lasting and resistant to rust and corrosion.

Prevent burnt electrodes. Used spark plugs may have a slight discoloration at the electrode (negative probe). Further inspection may reveal that the gap between the ground electrode and the center electrode is wider. If the gap is not properly aligned, the electrode will continue to discolor and will eventually burn away. 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 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. 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.

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. 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.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. Gauges have multiple uses in automotive manufacturing work. Many machinists use these types of gauges daily, and a mechanic cannot be without a set of tune-ups. Whether you are looking for that perfect spark plug gap or precision in your parts, feeler gauges, used effectively, can be a must. A wire-type feeler gauge is a little different to the standard shim arrangement. Instead of featuring a series of graded metal leaves or blades, the wire feeler gauge instead has a series of rigid metal wires.

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.

Halfords Spark Plug Gauge Metric

Some of the most common sizes you will likely find yourself using include 1mm, 1.5mm and 2mm feeler gauges. However, the ones you tend to use the most will of course depend largely on what type of work you are doing. 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.