Brinell • Rockwell • Vickers — Simulate • Explore • Practice • Quiz
Hardness testing is one of the most widely used mechanical tests in materials science and manufacturing quality control. It measures a material's resistance to permanent deformation — specifically, its resistance to localized plastic deformation caused by an indenter being pressed into the surface under a controlled load. Unlike tensile or impact tests that destroy the specimen, most hardness tests are non-destructive or semi-destructive, leaving only a small indentation on the surface. This makes hardness testing ideal for incoming material inspection, process control, and failure analysis.
Developed by Johan August Brinell in 1900, the Brinell test uses a hardened steel or tungsten carbide ball (typically 10 mm diameter) pressed into the surface under loads ranging from 500 to 3000 kgf. After removing the load, the diameter of the resulting circular impression is measured using a microscope. The Brinell Hardness Number (BHN) is calculated as: BHN = 2F / [πD(D − √(D² − d²))], where F is the applied force in kgf, D is the ball diameter in mm, and d is the impression diameter in mm. The Brinell test is especially suitable for materials with coarse or heterogeneous microstructures, such as castings and forgings, because the large indentation averages out local variations.
The Rockwell test, developed by Stanley Rockwell in 1914, is the most commonly used hardness test in industry due to its speed and simplicity. It measures hardness based on the depth of penetration rather than the size of the indentation. A minor load (10 kgf) is first applied to seat the indenter and establish a reference position. Then a major load is applied (60, 100, or 150 kgf depending on the scale) and removed, leaving only the minor load. The permanent increase in depth of penetration is used to calculate the hardness number. Scale C (HRC) uses a diamond cone indenter with 150 kgf major load and is used for hardened steels. Scale B (HRB) uses a 1/16" steel ball with 100 kgf for softer materials. The direct-reading dial eliminates the need for microscopic measurement, making it the fastest production hardness test.
The Vickers test, developed in 1921 by Robert Smith and George Sandland at Vickers Ltd, uses a diamond pyramid indenter with an included angle of 136° between opposite faces. The test load can range from 1 to 120 kgf (macro) or as low as 10 gf for microhardness testing. After load removal, both diagonals of the square impression are measured under a microscope and averaged. The Vickers Hardness Number is: HV = 1.854F / d², where F is in kgf and d is the mean diagonal in mm. A key advantage of the Vickers test is that the hardness number is independent of load — unlike Brinell, which requires specific load-to-diameter ratios. This makes the Vickers scale continuous across all materials from soft aluminium to the hardest steels.
In Simulate mode, select a test method (Brinell, Rockwell, or Vickers), choose a material, adjust the load and indenter parameters, and click "Run Test" to watch an animated indentation sequence. The simulator calculates the correct impression size from known material hardness values and displays the hardness number, indentation measurement, and all test parameters. Switch to Explore mode to study 12 concepts covering test methods, indenter types, scale selection, and hardness conversions. Practice mode generates random calculation problems with step-by-step solutions, and Quiz tests your knowledge with 5 questions per session covering both theory and numerical problems.
This hardness testing simulator is designed for mechanical engineering students, materials science trainees, quality control inspectors, metallurgists, and manufacturing technicians. It provides a safe, interactive way to learn hardness testing procedures, understand the differences between test methods, and practise hardness number calculations without requiring expensive testing equipment or material specimens.