Andreas Bohren and Stefan Brunold
Description of the Specific Test and Test Procedure
Two different test procedures for the assessment of impact resistance are found in the different international test and certification standards. Depending on the standard there are only some minor differences in the application.
One method involves using steel balls dropping from increasing heights on the collector. In the second method laboratory ice stones of different sizes fired with well – defined speed onto the collector. The rating of the impact resistance is based on the maximum impact energy (impact speed, falling height) without damage to the collector. Obviously, the two methods are not really comparable as the two impact projectiles have completely different physical properties (hardness, weight). It is furthermore common sense that the steel ball method is reasonable for simulating tool impact testing, while the ice ball method is better suited to simulating hail impact.