Feeler Gauges

Feeler gauges are handheld tools that are used to measure the distance between two objects, specifically very small distances between two components in a system. They utilise short, rounded blades of different, precise thicknesses to perform the measurement, where the user slides the blade between two objects to determine the distance. Commonly used in automotive servicing, engineering, and general maintenance applications, feeler gauges are an essential tool wherever precise gap measurement is required. RS New Zealand stocks a wide range of feeler gauges from trusted brands to ensure accurate, reliable measurements across any application.

How Do Feeler Gauges Work?

Feeler gauges work by inserting individual blades into a gap until the correct thickness is found. The user selects a blade and slides it into the gap between two components. A correctly sized blade will pass through with a slight, consistent resistance, indicating the gap matches the blade thickness. Where a single blade does not achieve the required measurement, multiple blades can be stacked and inserted together to reach a specific combined thickness. This method allows for highly precise clearance measurement across a wide range of applications. Accurate gap measurement is essential for equipment performance and preventive maintenance, as incorrect clearances can lead to premature wear, poor performance, or component failure over time.

Types of Feeler Gauges

Imperial and Metric Feeler Gauges

Feeler gauges are available in both imperial and metric versions to suit different working environments and standards. A metric feeler gauge displays blade thicknesses in millimetres, while an imperial feeler gauge uses inch measurements. Combination sets covering both systems are also available for workshops that work across multiple standards.

Standard Blade Feeler Gauges

Standard blade feeler gauges are the most widely used type, featuring straight blades of varying thicknesses suited to general-purpose gap measurement. They are a practical choice for automotive servicing, engineering workshops, and routine maintenance tasks where straightforward access to the gap is available and no specialist blade geometry is required.

Offset Feeler Gauges

Offset feeler gauges feature blades set at an angle relative to the handle, allowing access to gaps in confined or awkward spaces where a straight blade cannot reach. They are commonly used in engine bays, machinery assemblies, and other applications where the measurement point is partially obstructed or positioned at a difficult angle.

Long Blade Feeler Gauges

Long blade feeler gauges are designed for deep gaps and hard-to-reach measurement points where a standard-length blade would be insufficient. The extended blade length allows the tool to reach recessed or deeply set clearances without compromising measurement accuracy, making them well suited to large machinery and industrial equipment maintenance.

Tapered Feeler Gauges

Tapered feeler gauges feature a blade that gradually changes in thickness along its length, allowing the user to determine gap width by noting where resistance is felt along the taper. They are particularly useful for measuring varying or non-uniform gap widths where a fixed-thickness blade may not give a clear reading.

Feeler Gauge Sets

A feeler gauge set contains multiple blades of different thicknesses housed in a single, foldable tool, providing versatile measurement capability across a wide range of gap sizes. Sets are available in metric, imperial, and combination configurations, making them a practical all-in-one solution for workshops and technicians who encounter varied measurement requirements regularly.

Feeler Gauge Materials

Depending on the job, you might want to keep a few different feeler gauges made of different materials on hand. Typically, feeler gauges are made from a sturdy metal to ensure the blades retain their structure after heavy use. However, it is also common to see plastic feeler gauges used to measure gaps between delicate instruments or magnetised surfaces. Plastic feeler gauges are also more cost-effective, but may suffer from wear and tear faster than stainless steel feeler gauges.

Features and Benefits of Feeler Gauges

Feeler gauges offer a combination of precision, durability, and ease of use that makes them a reliable choice for accurate gap measurement across a wide range of applications. Key features and benefits include:

• Precision-ground blades: Each blade is ground to an exact thickness, ensuring accurate and repeatable measurements that support improved maintenance accuracy and reliable inspection results.
• Stainless steel or hardened steel construction: Robust blade materials resist deformation and corrosion under regular use, extending the service life of the tool and reducing equipment wear over time.
• Multiple blade thickness options: A wide range of blade thicknesses within a single set allows the tool to cover different measurement requirements across automotive, engineering, and maintenance applications.
• Foldable designs: Blades fold neatly into the handle when not in use, protecting the blade edges and making the tool easy to carry in a toolbox or pocket.
• Clearly marked measurements: Each blade is engraved or stamped with its thickness, making identification fast and reducing the risk of selecting the wrong blade during measurement tasks.

How to Choose a Feeler Gauge

Selecting the right feeler gauge depends on the application, the gap sizes involved, and the working environment. Consider the following factors:

• Measurement range: Select a feeler gauge or feeler gauge set that includes blade thicknesses suited to the clearances you need to measure, ensuring coverage across your most common gap sizes.
• Number of blades: Larger sets offer greater flexibility across different measurement tasks, making them a more versatile investment for workshops and technicians with varied requirements.
• Blade material: Consider whether a stainless steel feeler gauge or hardened steel option is more appropriate based on the working environment, required durability, and any corrosion resistance needs.
• Measurement units: Choose a metric feeler gauge, an imperial feeler gauge, or a combination set based on the standards used in your application and the specifications you are working to.
• Blade style: Select straight blades for general access, offset blades for confined spaces, or tapered blades for varying gap widths, depending on the accessibility and geometry of the measurement point.
• Application requirements: Consider whether the gauge will be used for automotive repair, precision engineering, or industrial maintenance, as each may have specific requirements around blade length, thickness range, or material.

Applications of Feeler Gauges

Feeler gauges are used across a wide range of industries and trades wherever precise gap measurement is essential to performance, safety, or compliance. Common applications include:

• Automotive servicing: Feeler gauges are a standard tool for valve clearance checks and spark plug gap adjustment, where precise clearances are critical to engine performance and reliability.
• Machinery maintenance and inspection: Regular gap checks on rotating and reciprocating machinery components support machine safety by identifying wear or misalignment before it leads to failure or unplanned downtime.
• Engineering and manufacturing applications: Feeler gauges are used alongside micrometers and other precision instruments to verify component clearances, fits, and tolerances during production and assembly.
• Quality control processes: Gap measurement with a feeler gauge provides a fast, reliable method for inspecting components against specification during incoming goods checks or final inspection stages.
• Workshop repairs and equipment servicing: Technicians across automotive, electrical, and mechanical trades use feeler gauges during routine servicing to confirm clearances are within the manufacturer's specified range.
• Precision measurement tasks: Any application requiring accurate gap checks between mating surfaces, including gearbox shimming, bearing fits, and brake component inspection, benefits from the precision a quality feeler gauge provides.

Find the Right Feeler Gauge for Your Job Today

Whether you need a single stainless steel feeler gauge for automotive work or a complete feeler gauge set for a busy workshop, RS New Zealand has the right tool for the job. Browse our full range online to find the blade thicknesses, materials, and configurations that match your application, and enjoy fast, reliable delivery across NZ.

Your Trusted Supplier & Distributor of Feeler Gauges

RS New Zealand is a trusted supplier and distributor of high-quality feeler gauges. We offer an extensive range of feeler gauges from reputable brands, such as Precision Brand, Vogel, and RS PRO,, ensuring you have access to reliable, high-performance products for any application.

Beyond feeler gauges, we also offer a range of measuring and marking tools, such as laser levels and machinist squares, for all precision measurement and inspection requirements.

Explore our user-friendly online site for the full range of products and have them shipped directly to your site or home at your convenience. With our flexible delivery options, you can receive your products precisely when needed. For comprehensive details on delivery times and fees across New Zealand, please consult our Delivery page.