Information on the most widely used ASTM standards within the materials testing industry
Rockwell Hardness
Rockwell hardness is a measure of the resistance of a material to permanent indentation under a specific static load. It is defined based on the depth of indentation produced by a penetrator (either a diamond cone or a hardened steel ball) under two sequential loads: an initial minor load and a major load.
UnitedTest Rockwell Hardness Testing Machine
Dolphin nose indenter Dual Rockwell Hardness Tester
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Rockwell and Superficial Rockwell Dual Hardness Tester
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Touching Screen Rockwell Durometer
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Motorized Rockwell/Superficial Rockwell Hardness
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Dial Analog Rockwell Hardness Tester
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What's Rockwell hardness test?
Unlike Brinell or Vickers hardness (which rely on indentation area), Rockwell hardness is expressed as a numerical value combined with a scale symbol (e.g., HRC, HRB). The higher the value, the harder the material (with exceptions for some soft materials on specific scales).
The Rockwell hardness test follows a standardized, four-step process, with its core principle centered on indentation depth difference measurement:
1, Apply initial minor load (preload)
2, Apply major load
3, Remove the major load (retain minor load)
Common Penetrators and Loads (Typical Scales):
Rockwell Scale | Penetrator | Total Load | Application Scope |
HRC | 120° diamond cone | 150 kgf | Hardened steels, alloys (hard materials) |
HRB | 1.588 mm steel ball | 100 kgf | Mild steels, copper alloys, aluminum alloys (medium-soft materials) |
HRA | 120° diamond cone | 60 kgf | Thin hard materials, surface-hardened layers, cemented carbides |
Applications of Rockwell Hardness Test
The Rockwell test is one of the most widely used hardness testing methods in industrial and laboratory settings, thanks to its speed, simplicity, and non-destructive nature (indentations are small).
Key applications include:
Standards for Rockwell Hardness Test
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