Feeler Gauge Stock Rolls Guide: Materials, Sizes, Applications & Best Practices

Feeler gauge stock rolls are precision-manufactured strips of metal used for measuring narrow gaps and ensuring accurate alignment between components. Supplied in continuous coil form, they allow users to cut custom lengths for highly specific tasks. These rolls are commonly used in maintenance, calibration, manufacturing, tooling, and inspection workflows where precise dimensional control is essential.

1. What is a Feeler Gauge Stock Roll?

A feeler gauge stock roll is a long strip of calibrated, flat metal—typically spring steel or stainless steel—wound into a coil. Unlike traditional feeler gauges, which consist of pre-sized blades, stock rolls allow technicians to cut the exact length needed for specific jobs. This makes them highly adaptable for use in equipment maintenance, production line calibration, and dimensional inspection.

The material is ground to tight tolerances and often marked along its length for quick thickness identification. Most rolls are supplied in 5-metre lengths (or longer) and standard widths such as 12.7 mm (1/2"). Users can cut sections as required, reducing waste and increasing flexibility for both one-off and repetitive applications.

2. Materials and Mechanical Properties

Feeler gauge rolls are generally produced from two main types of precision strip:

• Hardened Carbon Spring Steel (Grade C75 or 1.1274): Provides excellent tensile strength, magnetic response, and wear resistance. Typically used in automotive and tooling applications where high fatigue strength is required.
• Stainless Steel (Grade 304 or similar): Offers corrosion resistance and is non-magnetic in annealed form. Often chosen for chemical processing environments, medical tooling, or clean room settings.

Typical mechanical properties for spring steel rolls include tensile strengths of 1500–2100 MPa and hardness levels up to 48 HRC. Stainless steel variants may have slightly lower strength but greater corrosion durability, depending on the specific alloy and processing condition.

All materials used for feeler gauge rolls are cold-rolled and often surface-finished through grinding or polishing to maintain dimensional consistency and surface uniformity. For more information, check our full Stainless Steel Grades Guide.

3. Size Availability and Tolerances

Feeler gauge rolls are manufactured in a wide range of calibrated thicknesses, typically starting from 0.01 mm up to 1.00 mm. Standard increments are available in both metric and imperial formats to support legacy machinery as well as metric-standard equipment.

The most commonly stocked width is 12.7 mm (1/2”), though other widths may be available for specialist applications. Thickness tolerances are usually within ±0.002 mm to ±0.005 mm, depending on the size and manufacturing specification. You can also refer to our full Shim Thickness Conversion Chart.

Thickness (mm)	Inches	Tolerance (± mm)	Standard Width	Material Options
0.01	0.0004"	0.002	12.7 mm	Carbon Steel
0.02	0.0008"	0.002	12.7 mm	Carbon Steel
0.03	0.0012"	0.002	12.7 mm	Stainless Steel
0.04	0.0016"	0.002	12.7 mm	Stainless Steel
0.05	0.0020"	0.002	12.7 mm	Both
0.06	0.0024"	0.003	12.7 mm	Both
0.07	0.0028"	0.003	12.7 mm	Both
0.08	0.0031"	0.003	12.7 mm	Both
0.09	0.0035"	0.003	12.7 mm	Both
0.10	0.0040"	0.003	12.7 mm	Both
0.12	0.0047"	0.003	12.7 mm	Both
0.15	0.0059"	0.004	12.7 mm	Both
0.18	0.0071"	0.004	12.7 mm	Carbon Steel
0.20	0.0079"	0.004	12.7 mm	Carbon Steel
0.25	0.0100"	0.005	12.7 mm	Carbon Steel
0.30	0.0118"	0.005	12.7 mm	Carbon Steel
0.35	0.0138"	0.005	12.7 mm	Carbon Steel
0.40	0.0157"	0.005	12.7 mm	Carbon Steel
0.45	0.0177"	0.005	12.7 mm	Carbon Steel
0.50	0.0197"	0.005	12.7 mm	Carbon Steel
0.55	0.0216"	0.005	12.7 mm	Carbon Steel
0.60	0.0236"	0.005	12.7 mm	Carbon Steel
0.65	0.0256"	0.005	12.7 mm	Carbon Steel
0.70	0.0276"	0.005	12.7 mm	Carbon Steel
0.75	0.0295"	0.005	12.7 mm	Carbon Steel
0.80	0.0315"	0.005	12.7 mm	Carbon Steel
0.85	0.0335"	0.005	12.7 mm	Carbon Steel
0.90	0.0354"	0.005	12.7 mm	Carbon Steel
0.95	0.0374"	0.005	12.7 mm	Carbon Steel
1.00	0.0394"	0.005	12.7 mm	Carbon Steel

4. Industrial and Technical Applications

Feeler gauge rolls are essential in settings where measurement precision and repeatability are critical. Some common application areas include:

• Automotive & Transport: Valve lash adjustments, camshaft end float checks, and gearbox alignment.
• Aerospace: Rotor spacing, bearing housing clearance, and turbine blade calibration.
• Precision Engineering: Tool and die setting, jig fitting, and quality control verification.
• Machine Maintenance: Checking wear clearances on rotating shafts, couplings, or guides.
• Instrumentation & Calibration: Gauge block comparison, sensor alignment, and micrometer validation.

For custom-cut precision profiled shapes, visit our Laser Cutting Services page .

5. Differences vs Shim Stock

Although both feeler gauge rolls and shim stock are used to fill gaps or set tolerances, they serve different functions and are not directly interchangeable.

Feature	Feeler Gauge Stock Roll	Shim Stock
Form	Coiled strip (typically 12.7 mm wide)	Flat sheet (various sizes)
Purpose	Measurement, calibration	Load-bearing spacing
Markings	Thickness-etched or labelled	Often unmarked
Material Hardness	High consistency	Varies by spec
Load Tolerance	Not for structural use	Can be load-bearing

In practice, a feeler gauge roll is used when precision measurement is required, while shim stock is used to create semi-permanent spacers or packers in assembled structures.

6. Cutting, Handling, and Safety

Feeler gauge strips are supplied in hardened metal, and as such they must be handled with care. Cutting should be performed using precision snips, shears, or dedicated gauge cutters to ensure a clean edge and avoid distortion. Avoid general-purpose scissors or tools that may crush the edge.

When cutting or handling sharp lengths, always wear appropriate PPE including gloves and eye protection. Cut ends can be razor-sharp and may pose a laceration risk. Rolled coils should be uncoiled carefully to avoid spring tension recoil or tangling. After cutting, any burrs should be lightly filed to prevent injury or equipment scratching.

7. Storage Guidelines and Operator Notes

To preserve the calibration and usability of feeler gauge rolls, storage should follow good engineering practice. Rolls should be stored in dry, sealed containers to prevent corrosion or contamination. Stainless steel rolls are more resistant to oxidation but should still be kept clean and free of moisture or chemical exposure.

Avoid storing rolls in direct sunlight or in locations with large thermal variation, which could introduce dimensional instability in extreme conditions. Rolls should be clearly labelled and thicknesses double-checked prior to each use. For repeatable processes or audits, record the batch number and material specification as part of your inspection protocol.

8. Frequently Asked Questions

What is the difference between a feeler gauge and a shim?

Feeler gauges are used primarily for measurement—specifically to check clearance or gap sizes—while shims are used to fill those gaps and adjust alignment or positioning. Feeler gauges are temporary tools used during setup or inspection, whereas shims are often left in place as part of an assembly.

Can feeler gauge stock rolls be reused?

In most cases, feeler gauge strips are single-use to ensure accuracy. Once a strip has been bent, scratched, or contaminated, it may not provide a reliable thickness measurement. For best results, always use a fresh strip and dispose of damaged sections properly.

Do I need to calibrate feeler gauge material?

Factory-supplied feeler gauge rolls are ground to calibrated tolerances and do not require field calibration. However, for quality-critical applications, it's advisable to periodically verify thickness using a micrometer or calibration block, especially for ISO 17025-compliant workflows.

What tools are best for cutting feeler gauge rolls?

Specialist snips, high-precision shears, or feeler gauge cutters are ideal. Avoid using blunt scissors or wire cutters, which may deform the edge. For clean, burr-free cuts, dedicated bench tools or scissor-style cutters are recommended.

How should I store partially used rolls?

Store them in the original dispenser or a sealed container with humidity control. Always label the roll with the thickness, material type, and remaining length if known. Avoid exposure to temperature swings, moisture, or dust that can affect the surface finish.