IS 1586 covers the Rockwell hardness test — the fastest hardness test, widely used in production environments. Three main scales: HRA (thin hard materials), HRB (annealed steel, brass, aluminium), HRC (hardened steel, tool steel). Gives a direct reading — no microscope needed.
Method for determining Rockwell hardness (HRA, HRB, HRC) of metallic materials using diamond cone or steel ball indenters under specified loads.
Key Values
HRC range20-70 (hardened steel)
HRB range0-100 (soft/medium steel)
HRC test load150 kgf (1471.5 N)
Practical Notes
! HRC is THE standard hardness scale for hardened/heat-treated steel — most commonly specified in India.
! Rockwell is the fastest test (10 seconds per reading) — ideal for production line QC.
! No microscope needed — hardness value reads directly from the machine dial/display.
! For soft materials (annealed steel <20 HRC), use HRB scale. For hardened steel, use HRC.