14 Jul Understanding Rock Strength : The Rock Impact Hardness Number (RIHN) Test
BRTS will soon be accredited for this test and can help your rock mechanics and geotechnical evaluation. Whether you’re optimizing blast design, evaluating material for construction, or estimating crushing and grinding efficiency, one factor remains central: understanding the hardness and breakability of rock. That’s where the Rock Impact Hardness Number (RIHN) Test can make a significant impact.
What Is the RIHN Test?
The RIHN Test is a modernized version of the Protodyakonov Strength Index. Enhanced for consistency and repeatability, the RIHN test performed by BRTS uses standardized core samples to simulate real-world breakage scenarios and quantify the samples’ resistance to impact forces.
A Simple Concept with Powerful Results
A number of rock specimens having the same dimensions are subjected to different kinetic energies, produced by different numbers of hammer blows, and the degrees of comminution produced by each test are analysed, to indicate the amount of kinetic energy to produce an arbitrary 25% comminution. The RIHN, the number of hammer blows required to produce 25% comminution, is a fundamental characteristic of each rock type, enabling quantitative comparisons of the amount of work required to break or cut different rocks, providing insights essential for:Mining operations – Improve drill-and-blast strategies
Crushing circuit design – Predict energy requirements
Construction and tunnelling – Predict machine productivity and tool wear
Rock mass classification systems – Integrate mechanical behaviour into geotechnical models
Why Choose the RIHN Test from BRTS?
✅ Fast and cost-effective
✅ Reproducible and standardized
✅ Provides a bridge between lab results and field performance
✅ Ideal for comparative studies – Easily compare rock types across mine sites or formations
Proven in the Field
From exploration drilling programs to academic research, the RIHN Test has been adopted worldwide as a practical solution for characterizing rock strength. It helps stakeholders make data-driven decisions—from resource planning to equipment specification.
Get Ahead with RIHN – Powered by BRTS
If you’re seeking a practical method to evaluate rock breakability, the Rock Impact Hardness Number Test delivers. Contact us today to learn how RIHN testing with NATA accreditation can be integrated into your next project
