Comparison of HRC HRB and HV hardness testing methods 

1. HRC (Rockwell Hardness Scale C)

• Principle: Measures hardness using a diamond cone indenter (120° angle) under a major load of 150 kgf, based on penetration depth.
• Application:
  • High-hardness materials (e.g., hardened steel, tool steel, carbides).
  • Typical range: 20–70 HRC (inaccurate below 20 HRC due to excessive penetration).
• Features:
  • Fast and suitable for mass testing.
  • Large indentation, not ideal for thin or small parts.

2. HRB (Rockwell Hardness Scale B)

• Principle: Uses a 1.588mm steel ball indenter with a 100 kgf major load to measure penetration depth.
• Application:
  • Softer materials (e.g., annealed steel, copper, aluminum, brass).
  • Typical range: 20–100 HRB (switching to HRC is needed above 100 HRB to avoid ball deformation).
• Features:
  • Prevents indenter damage on soft materials.
  • Unsuitable for very hard or thin specimens.

3. HV (Vickers Hardness)

• Principle: Employs a diamond pyramid indenter (136° angle) under light loads (1–100 kgf). Hardness is calculated from the diagonal length of the square-shaped indentation.
• Application:
  • Thin coatings, surface layers, ceramics, and microstructures.
  • Universal: covers all materials (soft to ultra-hard).
• Features:
  • Small, precise indentations, requires microscopic measurement.
  • Time-consuming but highly accurate.

Key Differences Summary

How to Choose?

• High hardness (e.g., blades): HRC.
• Soft metals (e.g., annealed parts): HRB.
• Thin layers or research: HV.

Note: HRC/HRB are Rockwell scales (fast but less precise for thin samples). HV is versatile but slower. Selection depends on material properties and testing requirements.