Fit tolerance is allowable size of the product in manufacturing used. For example, the tolerance for φ20H7 hole product is [+0.021_0], which means the allowable maximum and minimum size of the hole is φ20.021 and φ20, respectively.

A pair of GO and NO GO limit plug gauge is used for inspecting minimum and maximum size hole, respectively. Each plug gauge has its manufacturing tolerances. For example, manufacturing tolerance for GO plug gauge is φ20.0 +0.001/+0.005, and NO GO plug gauge is φ20.021 ±0.002.

A calibration certificate is generally a document that verify the capability and performance of an item of measuring and test equipment by comparison to traceable measurement standards.

Together with calibration certificate, we also issue traceable certificate, traceability system diagram, report on the judgement result, and calibration and inspection certificates of the instruments used for calibration. You are liable for certificate issuing fee.

Accurate gauge with air tooling depends on the ability of the tool to produce consistent measurements, regardless of the tool's position within the workpiece. This means that the airflow and characteristics of the two jets must be "balanced". Since the air amplifier reacts to changes in this airflow, any position of the tool in the workpiece which reduces the airflow from one jet, must create a proportionate increase in airflow from an opposing jet. Jet diameters and "nozzle drops" must be identical, and on a common centerline with the outer diameter of the plug itself.

Any deviation in these two conditions of "balance" and "centrality" will cause indicator fluctuations commonly referred to as "total shake error". The following test procedures are recommended as the best methods of determining when an air tool should be removed from service. (Note these are only generalized recommendations and the results from each of these tests should be considered against the tolerance being measured with any specific air tool).

Accurate gauge with air tooling depends on the ability of the tool to produce consistent measurements, regardless of the tool's position within the workpiece. This means that the airflow and characteristics of the two jets must be "balanced". Since the air amplifier reacts to changes in this airflow, any position of the tool in the workpiece which reduces the airflow from one jet, must create a proportionate increase in airflow from an opposing jet. Jet diameters and "nozzle drops" must be identical, and on a common centerline with the outer diameter of the plug itself.

Any deviation in these two conditions of "balance" and "centrality" will cause indicator fluctuations commonly referred to as "total shake error". The following test procedures are recommended as the best methods of determining when an air tool should be removed from service. (Note these are only generalized recommendations and the results from each of these tests should be considered against the tolerance being measured with any specific air tool).

We can not predict the lifetime of the gauges. The actual number of parts tested (frequency of use), the cleanliness of the gauges when testing it and the tightness of the gauges to part, all have an impact on the certifiable life of gauges.

The gauges are subject to wear during use. However, wear could be prevented by taking care the gauge from dust, chips, burr that sticking on the product. Clean the product from such the things before inspection using gauge.  

Warranty period is not particularly specified. We will examine and handle separately the damage or abnormal symptoms which occurs at normal usage in a short period after purchased.