30 Rebound Hardness
Rebound hardness, also known as dynamic hardness, measures the height of the “bounce” of a diamond-tipped hammer dropped from a fixed height onto a material. This type of hardness is related to elasticity. The device used to take this measurement is known as a scleroscope. Two scales that measures rebound hardness are the Leeb rebound hardness test and Bennett hardness scale.
A scleroscope is a device used to measure rebound hardness. It consists of a steel ball dropped from a fixed height. The device was invented in 1907.
Video
Watch this 0:20 demonstration video Rebound hardness test, Antonio Georgiev, November 1, 2016.
As an improvement on this rough method, the Leeb Rebound Hardness Test, invented in the 1970s, uses the ratio of impact and rebound velocities (as measured by a magnetic inducer) to determine hardness.
Video
Watch this animated youtubeshort How Leeb hardness Tester work? #shorts #youtubeshorts #hardnesstestingmachine, by TechMechX, April 8, 2023.
Watch this 0:19 demonstration video Handheld Portable Leeb’s Rebound Hardness Tester by Landmark Precision, March 13, 2017.
Frequency Testing
Ultrasonic Contact Impedance (UCI) method determines hardness by measuring the frequency of an oscillating rod. The rod consists of a metal shaft with vibrating element and a pyramid-shaped diamond mounted on one end.
Videos
Watch this 4:05 video Testing with UCI – How to measure the hardness with SONODUR 3 by Institut Dr. Foerster GmbH & Co, KG, August 26, 2022
Derived from Hardness – Wikipedia Available and accessed online February 2024.
Derived from Scleroscope – Wikipedia Available and accessed online 1 February 2024.