Feeler gauges are one of the most commonly used precision tools in a workshop. It is an essential item for a quick and easy to use.
What is a feeler gauge?
A feeler gauge is a steel precision measuring tool used to check spacing and gap tolerances during set-up, repair and maintenance.
As the parts are usually very precise and are unable to be differentiated by sight, each piece is usually marked with the thickness of the gauge in mm or in inches.
Feeler gauges are a quick and easy way to verify critical clearances of manufactured components from or to engineering drawings.
How do I use a feeler gauge?
Feeler gauges are either individually packed or in a stack. Simply select the thickness and length you wish to test, and stick it into the gap of the workpiece being measured.
What are feeler gauges made of?
Feeler gauges are commonly made from hardened spring steel.
Stainless steel gauges are made for corrosive or pharmaceutical areas.
Brass feeler gauges are made for electronics due to their anti-magnetic properties.
What factors are considered when using a feeler gauge?
Two main points are important - length of gauge and thickness.
Length so that the gauge can reach the depth of the workpiece comfortably.
Thickness as this is the measure of tolerance for the gap.
What are common sizes for feeler gauges?
Common sizes include 0.05mm till 1mm with a 100mm blade length. These gauges are usually attached to a screw.
Other common sizes include 150mm, 200mm 300mm all the way to 500mm. These can be individually packed.
Feeler gauges can also go up to 5m rolls, depending on their thickness and the ability to roll the steel.
Is it recommended to stack feeler gauges?
Stacking feeler gauges on top of each other is not recommended. Since feeler gauges are used for very precise measurements, there may still be gaps due to the differences in flatness between each gauge stacked. If the gap is unknown, it may be better to select a taper gauge instead.
Are there workshop norms for thickness gauges?
Yes there are workshop norms in DIN and ISO. Most feeler gauges can be rated by their tolerances for hardened spring band steel. Generally, the thicker the steel is, the more there will be some level of deviation in the thickness.
Below are the permissible tolerances for hardened spring band steel.
| Nominal Thickness (mm) |
T2 (A2) (+/- mm) |
T3 (A3) (+/- mm) |
| 0.03 / 0.04 / 0.05 / 0.06 | 0.004 | 0.003 |
| 0.07 / 0.08 / 0.09 / 1.00 | 0.005 | 0.004 |
| 0.11 / 0.12 / 0.13 | 0.005 | - |
| 0.14 / 0.15 | 0.006 | 0.005 |
| 0.16 / 0.18 | 0.007 | - |
| 0.2 | 0.008 | 0.006 |
| 0.22 / 0.24 | 0.008 | - |
| 0.25 | 0.009 | 0.006 |
| 0.28 | 0.009 | - |
| 0.30 | 0.009 | 0.007 |
| 0.35 | 0.011 | 0.007 |
| 0.40 / 0.45 | 0.012 | 0.008 |
| 0.50 / 0.55 | 0.014 | 0.009 |
| 0.60 / 0.65 | 0.014 | 0.009 |
| 0.70 /0.75 | 0.017 | 0.012 |
| 0.80 /0.85 | 0.019 | 0.013 |
| 0.90 / 0.95 | 0.022 | 0.014 |
| 1.00 | 0.024 | 0.016 |
| 1.10 | 0.024 | 0.017 |
| 1.20 | 0.024 | 0.018 |
| 1.30 | 0.028 | 0.019 |
| 1.40 | 0.028 | 0.021 |
| 1.50 | 0.028 | 0.022 |
| 1.60 | 0.033 | 0.023 |
| 1.70 | 0.033 | 0.024 |
| 1.80 | 0.033 | 0.026 |
| 1.90 | 0.035 | 0.027 |
| 2.00 | 0.035 | 0.028 |
You may see some of our feeler gauges here.
Should you have further questions or custom sizes, do contact us.
