It is used to assess the pliability of the paint film through the capability that the paint film deforms with bottom material and does not get damage at the specified standard conditions. It is expressed with the minimum shaft stick diameter which does not cause the paint film to crack when the test plate moves around the shaft stick of 180° within 1-3 seconds at the specific conditions in the standard. It confirms to ISO 1519 ,ASTM D 522,DIN 53152.

This tester consists of eight hinges and each hinge has different diameter axis. Put the test panels into hinge then fold it and test panels then have finished 180° bend.
The test can be carried out：

—either as a “pass/fail” test, by carrying out the test with a single specified size of mandrel, to assess compliance with a particular requirement;

—or by repeating the procedure using successively smaller mandrels to determine the diameter of the first mandrel over wich the coating cracks and/or becomes detached from the substrate.