A feeler gauge and a thickness gauge are both used to measure gaps and material thickness, but they function differently and serve distinct purposes.
1. Feeler Gauge: Gap Measurement
A feeler gauge is a mechanical tool consisting of multiple thin metal blades of varying thicknesses. It is used to measure small gaps or clearances between two surfaces, such as in engine components, manufacturing, and assembly applications.
- Usage Insert different blades into a gap until a snug fit is achieved.
- Measurement Range Typically 0.02 mm to 1 mm.
- Common Applications Engine valve clearance, bearing gaps, and machine alignment.
2. Thickness Gauge: Material Thickness Measurement
A thickness gauge is used to measure the absolute thickness of a material, such as metal sheets, films, and coatings. Unlike feeler gauges, thickness gauges provide a direct numerical measurement. There are different types of thickness gauges:
- Contact Thickness Gauges (VBM, VBK Series) – Measure thickness using physical contact sensors .
- Non-Contact Laser Gauges (VTLG Series) – Use laser triangulation to determine thickness .
- Ultrasonic and X-ray gauges – Measure material thickness in specialized applications.
Key Differences
| Feature | Feeler Gauge | Thickness gauges |
|---|---|---|
| Measurement | Gap between two surfaces | Direct thickness of a material |
| Method | Manual blade insertion | Digital, contact, or non-contact measurement |
| Accuracy | Depends on feel and fit | High precision (e.g., micrometers) |
| Applications | Engine clearance, machining | Sheet metal, coatings, films |
Which One to Use?
- Use a feeler gauge when measuring gaps or checking clearances.
- Use a thickness gauge when requiring precise, absolute material thickness measurements.
For high-precision thickness measurement, Vollmer offers VBK, VBM, and VTLG gauges designed for industrial applications. Contact us for the best measurement solutions.